Closed band for percutaneous annuloplasty

ABSTRACT

A method is provided, which includes providing an annuloplasty ring, which comprises (a) a flexible sleeve, and (b) a contracting assembly. During a percutaneous transcatheter procedure, the flexible sleeve is placed entirely around an annulus of a mitral valve of a subject in a closed loop. The sleeve is fastened to the annulus by coupling a plurality of tissue anchors to a posterior portion of the annulus, without coupling any tissue anchors to an anterior portion of the annulus between left and right fibrous trigones of the annulus. Thereafter, a longitudinal portion of the sleeve is contracted. Other embodiments are also described.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of U.S. applicationSer. No. 13/167,492, filed Jun. 23, 2011, which is assigned to theassignee of the present application and is incorporated herein byreference.

FIELD OF THE APPLICATION

Some applications of the present invention relate in general to valverepair, and more specifically to repair of an atrioventricular valve ofa patient.

BACKGROUND OF THE APPLICATION

Dilation of the annulus of the mitral valve prevents the valve leafletsfrom fully coapting when the valve is closed. Mitral regurgitation ofblood from the left ventricle into the left atrium results in increasedtotal stroke volume and decreased cardiac output, and ultimate weakeningof the left ventricle secondary to a volume overload and a pressureoverload of the left atrium. Dilation of the annulus is sometimestreated by annuloplasty, in which a partial or full ring is implantedaround the annulus to cause the leaflets to coapt when the valve isclosed.

SUMMARY

In some applications of the present invention, an implantable structureis provided that comprises a flexible sleeve having first and secondsleeve ends, a contracting assembly, and a plurality of tissue anchors.The contracting assembly is configured to longitudinally contract thesleeve, and comprises a contracting mechanism and a longitudinalcontracting member having first and second member ends. The contractingmechanism is disposed longitudinally at a first site of the sleeve, andthe second member end is coupled to the sleeve longitudinally at asecond site longitudinally between the first site and the second sleeveend, exclusive. The contracting member also has a first member endportion, which extends from the first member end toward the secondmember end along only a longitudinal portion of the contracting member,and is coupled to the contracting mechanism. A first portion of thesleeve longitudinally extends from the first sleeve end toward the firstsite, and a second portion of the sleeve longitudinally extends from thesecond sleeve end toward the second site. The sleeve is arranged in aclosed loop, such that the first and second portions of the sleevetogether define a longitudinally overlapping portion of the sleeve. Theimplantable structure is configured such that the contracting assemblyapplies a longitudinal contracting force only between the first and thesecond sites, and not along the overlapping portion. The longitudinalcontracting force longitudinally contracts at least a portion of thesleeve only between the first and the second sites, and not along theoverlapping portion. Typically, the contracting member extends alongneither the first nor the second portion of the sleeve.

In some applications of the present invention, the contracting assemblyincludes one or more longitudinal contracting members coupled to thecontracting mechanism. The implantable structure is placed completelyaround an annulus of an atrioventricular valve of a subject, such thatnone of the one or more longitudinal contracting members is positionedalong an anterior portion of the annulus between fibrous trigones of thevalve. The implantable structure is fastened to the annulus. Thecontracting assembly is then actuated to contract a longitudinal portionof the sleeve not positioned along the anterior portion of the annulus.Tightening of the implantable structure therefore tightens at least aportion of the posterior portion of the annulus, while preserving thelength of the anterior portion of the annulus. (The anterior portion ofthe annulus should generally not be contracted because its tissue ispart of the skeleton of the heart.) However, the portion of the sleevedeployed along the anterior portion of the annulus prevents dilation ofthe anterior annulus, because the sleeve is anchored at both ends of theanterior annulus, and the sleeve typically comprises a longitudinallynon-extensible material. This deployment configuration may help preventlong-term resizing of annulus, especially the anterior annulus, whichsometimes occurs after implantation of partial annuloplasty rings, suchas C-bands.

In some applications of the present invention, one or more of the tissueanchors are coupled to the sleeve at respective third siteslongitudinally between the second site and the second sleeve end,exclusive. Typically, the implantable structure is configured such thatthe contracting assembly applies a longitudinal contracting force onlybetween the first and the second sites. The longitudinal contractingforce contracts at least a portion of the sleeve only between the firstand the second sites. Providing the one or more anchors beyond the endsof the contracting member generally distributes force applied bycontraction of the contracting assembly over the tissue interfaces ofthese anchors. In contrast, in some configurations of the implantablestructure in which anchors are not provided beyond the ends of thecontracting member, the force applied by the contracting assembly isapplied predominantly to the single anchor nearest the first end of thecontracting member, and the single anchor nearest the second end of thecontracting member.

For some applications, at least two of the tissue anchors are coupled tothe sleeve at respective third sites longitudinally between the secondmember end and the second sleeve end, exclusive. For some applications,the second site is at least 5 mm from the second sleeve end, measuredwhen the sleeve is in a straight, relaxed, non-contracted state, such asat least 9 mm, e.g., at least 18 mm. For some applications, the secondsite is at a longitudinal distance from the second sleeve end, whichdistance is no greater than 30% of a total length of the sleeve, thedistance and length measured when the sleeve is in the straight,relaxed, non-contracted state. For some applications, at least three ofthe tissue anchors are coupled to the sleeve alongside the contractingmember, longitudinally between the first and second sites, exclusive.Typically, the sleeve is substantially longitudinally non-extensible.

For some applications, the sleeve has first and second sleeve ends, andfirst and second portions that longitudinally extend from the first andthe second sleeve ends, respectively. The sleeve is arranged in a closedloop, such that the first and second portions of the sleeve togetherdefine a longitudinally overlapping portion of the sleeve positioned atleast partially along the anterior portion of the annulus, and none ofthe one or more longitudinal contracting members is positioned along theoverlapping portion of the sleeve. For some applications, at least oneof the tissue anchors penetrates both the first and second portions ofthe sleeve at the overlapping portion. Such a mutual anchor helps ensurethat the first and second portions remain tightly coupled together andto the tissue, so that the sleeve retains its closed loop shape.Alternatively, for some applications, the sleeve is shaped so as todefine an integrally closed loop having no sleeve ends.

The implantable structure, when in this closed-loop configuration, isdeployed around the entire annulus of the native valve, including ananterior portion of the annulus (on the aortic side of the valve)between the fibrous trigones. Typically, the contracting member does notextend along the portion of the sleeve deployed along the anteriorportion of the annulus, and thus does not extend along the firstportion, the second portion, or the overlapping portion of the sleeve.The portion of the sleeve deployed along the anterior portion of theannulus (between the trigones) is thus non-contractible. As mentionedabove, tightening of the implantable structure therefore tightens theposterior portion of the annulus, while preserving the length of theanterior portion of the annulus. For some applications, this deploymentconfiguration may also help achieve a closed loop that serves as a basering to which a prosthetic valve is coupled.

In some applications of the present invention, the implantable structurefurther comprises an elongated linking member, which is positioned alongan anterior portion of the annulus, so as to join the ends of theimplantable structure in a complete loop. Over time after implantation,the linking member becomes fixed to the anterior portion of the annulus,thereby helping prevent long-term dilation of the anterior annulus.Typically, at least a portion of the linking member is disposed withinand covered by the sleeve, into and/or over which fibrous tissue growsover time, helping anchor the linking member to tissue of the anteriorannulus. Typically, in this configuration of the implantable structure,none of the anchors is coupled to the anterior portion of the annulus.

A first end of the linking member is typically fixed between 2 and 6 cmfrom a first end of the sleeve. A second end of the linking member ispositioned within 1.5 cm of the same end of the sleeve, eitherprotruding from the end of the sleeve, or recessed within the sleeve.The second end of the linking member comprises (e.g., is shaped so as todefine) a first coupling element. The implantable structure furthercomprises a second coupling element, which is configured to becoupleable to the first coupling element. The second coupling element iscoupled to the implantable structure within 1.5 cm of the second end ofthe sleeve. The second coupling element may be coupled to the housing,directly to the sleeve, or otherwise coupled to the implantablestructure. Typically, the linking member is substantially longitudinallynon-extensible, i.e., its length is fixed.

For some applications, the linking member is configured as a spring,which is typically curved, so as to be elastic in a radial direction,i.e., to be compressible like a bow or deflected beam. In theseapplications, the linking member is oriented such that it is pressed byelasticity against the anterior portion of the mitral annulus, i.e., theouter wall of the aorta, thereby holding the sleeve covering the linkingmember against the aortic wall. For some applications, at least two ofthe tissue anchors are coupled to the sleeve at respective, differentlongitudinal sites alongside the linking member, within 6 cm of thefirst end of the linking member. These tissue anchors may help set theproper direction of curvature of the linking member, for applications inwhich the linking member is curved.

For some applications, the implantable structure further comprises anelongated radial-force application element, which is disposed entirelywithin a first longitudinal portion of the sleeve. The elongatedradial-force application element is configured to apply a force againsta wall of the first longitudinal portion of the sleeve in at least oneradially-outward direction. The applied force pushes the firstlongitudinal portion of the sleeve against tissue of the left atrium,such as against tissue of the annulus and/or the atrial wall, so as toinhibit blood flow between the sleeve and the tissue. It is generallydesirable to inhibit blood flow between the sleeve and the annulus onanterior side, to avoid creating turbulence. When implanting theimplantable structure, the elongated radial-force application element isplaced along the anterior portion of the annulus, between the fibroustrigones.

For some applications, the elongated radial-force application elementcomprises a springy element. For some applications, at least a portionof the springy element is curved at least partially about an innersurface of the wall of the sleeve.

For some applications, the elongated radial-force application element isrotationally asymmetric and not helically symmetric. For otherapplications, the elongated radial-force application element ishelically symmetric; for these applications, the springy elementtypically comprises a coiled spring.

For some applications, the sleeve has first and second sleeve ends. Forsome applications, the elongated radial-force application element has(a) a first radial-force-application-element longitudinal end that isbetween 2 and 6 cm from the first sleeve end, measured when the sleeveis fully longitudinally extended, and (b) a secondradial-force-application-element longitudinal end that is within 1.5 cmof the first sleeve end, measured when the sleeve is fullylongitudinally extended.

For some applications, the annuloplasty ring further comprises (a) afirst coupling element, which is coupled to the annuloplasty ring within1.5 cm of the first sleeve end, measured when the sleeve is fullylongitudinally extended, and (b) a second coupling element. The secondcoupling element is configured to be coupleable to the first couplingelement, and is fixed to the implantable structure (e.g., theannuloplasty ring) within 1.5 cm of the second sleeve end, measured whenthe sleeve is fully longitudinally extended. For some applications, atleast one of the first and second coupling elements comprises a hook.

For some applications, the contracting mechanism (e.g., the housingthereof) is fixed along the sleeve within 30 mm, such as within 15 mm,of the second sleeve end (i.e., the same end of the sleeve near whichthe second coupling element is coupled), measured when the sleeve isfully longitudinally extended. For example, the contracting mechanism(e.g., the housing thereof) may be fixed at the second sleeve end.Alternatively, for some applications, the contracting mechanism (e.g.,the housing thereof) is fixed at least 5 mm from the second sleeve end,e.g., between 5 and 30 mm, such as between 5 and 15 mm, from the secondsleeve end. The second coupling element may be coupled to thecontracting mechanism (e.g., to the housing).

For some applications, the annuloplasty ring further comprises asubstantially longitudinally non-extensible linking member, i.e., alength thereof is substantially constant, i.e., cannot be longitudinallystretched, under normal usage conditions. The linking member typicallyhelps prevent long-term dilation of the anterior annulus. The linkingmember is typically configured not to apply any force to the wall of thefirst longitudinal portion of the sleeve. Typically, the linking memberis not configured as a spring.

For some applications, at least the first longitudinal portion of thesleeve is substantially longitudinally non-extensible, i.e., a lengththereof is substantially constant, i.e., cannot be longitudinallystretched, under normal usage conditions. In these applications, thefirst longitudinal portion typically helps prevent long-term dilation ofthe anterior annulus. For some applications, the first coupling elementis fixed to the wall of the sleeve within 1.5 cm of first sleeve end 51,measured when the sleeve is fully longitudinally extended. Theimplantable structure typically does not comprise the linking member inthese applications. In these applications, at least the firstlongitudinal portion of the sleeve is substantially longitudinallynon-extensible, and the first longitudinal portion typically helpsprevent long-term dilation of the anterior annulus.

For some applications, during placement, after fastening the sleeve tothe portion of the annulus, the healthcare professional twists the firstlongitudinal portion of the sleeve. Optionally, such twisting may serveone or both of the following purposes: (1) the twisting may store energyin the springy element for exertion of torque against the wall of thesleeve, and (2) the twisting may rotationally align the springy elementin the desired radial direction. Alternatively or additionally totwisting for the first of these purposes, the springy element may bepre-loaded (twisted) to store energy before implantation in the subject,such as immediately before implantation or during manufacture.

For some applications, the sleeve is fastened to the annulus by couplinga plurality of tissue anchors to the annulus. The tissue anchors arecoupled with:

-   -   a first non-zero longitudinal density along a posterior portion        of the annulus between the left and right fibrous trigones of        the annulus, including the trigones, which density is equal        to (a) a number of the tissue anchors coupled to the annulus        along the posterior portion of the annulus divided by (b) a        length of the posterior portion of the annulus (measured along        the annulus),    -   and a second non-zero longitudinal density along the anterior        portion of the annulus between the left and right fibrous        trigones of the annulus, not including the trigones, which        density is equal to (a) a number of the tissue anchors coupled        to the annulus along the anterior portion of the annulus divided        by (b) a length of the anterior portion of the annulus (measured        along the annulus).

The first longitudinal density is greater than the second longitudinaldensity. For some applications, the first longitudinal density is atleast twice the second longitudinal density, such as at least 2.5 thesecond longitudinal density, e.g., at least 3 times the secondlongitudinal density. After the tissue anchors are fastened to theannulus, a longitudinal portion of the sleeve is contracted, such as bycausing the longitudinal contracting member to apply a force to thelongitudinal portion of the sleeve, such as by actuating the contractingassembly.

For some applications, the sleeve is fastened to the annulus by couplinga plurality of tissue anchors to the annulus, including first, second,and third tissue anchors, as follows:

-   -   one or more first tissue anchors are coupled to the annulus        along a lateral scallop (P1) of the posterior leaflet, with a        first longitudinal density, which density is equal to (a) a        number of the first tissue anchors coupled to the annulus along        the lateral scallop (P1) divided by (b) a length of the lateral        scallop (P1) along the annulus,    -   a plurality of second tissue anchors (e.g., at least 3 tissue        anchors) are coupled to the annulus along a middle scallop (P2)        of the posterior leaflet, with a second longitudinal density,        which density is equal to (a) a number of the second tissue        anchors coupled to the annulus along the middle scallop (P2)        divided by (b) a length of the middle scallop (P2) along the        annulus, and    -   one or more third tissue anchors are coupled to the annulus        along a medial scallop (P3) of the posterior leaflet, with a        third longitudinal density, which density is equal to (a) a        number of the third tissue anchors coupled to the annulus along        the medial scallop (P3) divided by (b) a length of the medial        scallop (P3) along the annulus.

The longitudinal densities are characterized by at least one of thefollowing: (a) the second longitudinal density is at least twice thefirst longitudinal density, and (b) the second longitudinal density isat least twice the third longitudinal density. For some applications,both (a) the second longitudinal density is at least twice the firstlongitudinal density, and (b) the second longitudinal density is atleast twice the third longitudinal density.

For some applications, the tissue anchors, including the second tissueanchors, comprise respective anchor heads and tissue coupling elements.Typically, the anchor heads are circular; alternatively, they haveanother shape, such as of an ellipse or a polygon (e.g., a hexagon or asquare). The plurality of tissue anchors are coupled to the annulus suchthat, after the longitudinal portion of the sleeve has been contracted,each of the anchor heads of at least two of the second tissue anchorscoupled along the middle scallop (P2) touches at least onelongitudinally-adjacent anchor head; for example, each of the anchorheads of at least three of tissue anchors touches at least onelongitudinally-adjacent anchor head 320.

Typically, before the longitudinal portion of the sleeve has beencontracted, the anchor heads of the at least two of the second tissueanchors do not touch any longitudinally-adjacent the anchor heads.Before the longitudinal portion of the sleeve has been contracted, theanchors are coupled to the sleeve and tissue at distances between theanchors that are less than the planned distances that the anchors movetoward each other during contraction of the longitudinal portion of thesleeve. As a result, the anchor heads touch each other upon suchcontraction.

This touching of the longitudinally-adjacent anchors heads inhibitslongitudinal contraction of the sleeve in the longitudinal area of theseanchors, so as to facilitate reshaping of the annulus in a desiredmanner. These longitudinally-adjacent the anchor heads thus aredual-function, and serve to both anchor their respective anchors to thesleeve and to inhibit contraction of the sleeve.

For some applications, the plurality of tissue anchors is coupled to theannulus such that, after the longitudinal portion of the sleeve has beencontracted:

-   -   none of the anchor heads of the first tissue anchors coupled        along the lateral scallop (P1) touches any of the other anchor        heads of the tissue anchors; and/or    -   none of the anchor heads of the third tissue anchors coupled        along the medial scallop (P3) touches any of the other anchor        heads of the tissue anchors.

For some applications, the plurality of tissue anchors are coupled tothe annulus such that, after the longitudinal portion of the sleeve hasbeen contracted:

-   -   a first number of the anchor heads of the first tissue anchors        coupled along the lateral scallop (P1) touch at least one        longitudinally-adjacent anchor head, and (b) a second number of        the anchors heads of the tissue anchors coupled along the middle        scallop (P2) touch at least one longitudinally-adjacent anchor        head, the second number greater than the first number; and/or    -   a second number of the anchor heads of the second tissue anchors        coupled along the middle scallop (P2) touch at least one        longitudinally-adjacent anchor head, and (b) a third number of        the anchors heads of the third tissue anchors coupled along the        medial scallop (P3) touch at least one longitudinally-adjacent        anchor head, the second number greater than the third number.

For some applications, the sleeve is fastened to the annulus by couplinga plurality of tissue anchors to the annulus, such that:

-   -   a first set of exactly three of the tissue anchors is disposed        in succession along a first portion of the longitudinal        contracting member with a first distance between        longitudinal-end tissue anchors of the first set, measured along        the annulus, and    -   a second set of exactly three of the tissue anchors is disposed        in succession along a second portion of the longitudinal        contracting member with a second distance between        longitudinal-end tissue anchors of the second set, measured        along the annulus,

The first distance equals at least twice the second distance, such as atleast 2.5 times the second distance, e.g., at least 3 times the seconddistance. The first distance is measured between closest portions of thelongitudinal-end tissue anchors of the first set, and the seconddistance is measured between closest portions of the longitudinal-endtissue anchors of the second set. The first and second sets do not shareany common tissue anchors. After the tissue anchors are fastened to theannulus, a longitudinal portion of the sleeve is contracted. Providingthe greater number of anchoring points with the second set betterdistributes forces among the anchors of this set.

For some applications, the contracting mechanism comprises a rotatablestructure, and a housing in which the rotatable structure is positioned.The contracting mechanism and the longitudinal contracting member arearranged such that rotation of the rotatable structure contracts theimplantable structure. Typically, an anchor deployment manipulator isadvanced into a lumen of the sleeve, and, from within the lumen, deploysthe anchors through a wall of the sleeve and into cardiac tissue,thereby anchoring the sleeve around a portion of a valve annulus.

For some applications, the implantable structure comprises an adjustableannuloplasty ring for repairing a dilated valve annulus of anatrioventricular valve, such as a mitral valve. The annuloplasty ringmay be used for treating functional mitral regurgitation (FMR) ordegenerative mitral valve disease. For other applications, a prostheticheart valve is further provided, which is configured to be coupled tothe sleeve.

For some applications in which the implantable structure is implantedaround the annulus of a valve, the implantable structure may be advancedtoward the annulus of a valve in any suitable procedure, e.g., atranscatheter procedure, a percutaneous procedure, a minimally invasiveprocedure, or an open heart procedure.

There is therefore provided, in accordance with an application of thepresent invention, a method including:

providing an annuloplasty ring, which includes (a) a flexible sleeve,and (b) a contracting assembly;

during a percutaneous transcatheter procedure, placing the flexiblesleeve entirely around an annulus of a mitral valve of a subject in aclosed loop;

fastening the sleeve to the annulus by coupling a plurality of tissueanchors to a posterior portion of the annulus, without coupling anytissue anchors to an anterior portion of the annulus between left andright fibrous trigones of the annulus; and

thereafter, contracting a longitudinal portion of the sleeve.

For some applications, the contracting assembly further includes alongitudinal contracting member and a locking mechanism, and the methodfurther includes, after contracting the longitudinal portion of thesleeve, locking the longitudinal contracting member with respect to thecontracting assembly using the locking mechanism.

For some applications, contracting the longitudinal portion of thesleeve includes actuating the contracting assembly to contract thelongitudinal portion of the sleeve.

For some applications, providing the annuloplasty ring includesproviding the annuloplasty ring in which the sleeve is shaped so as todefine an integrally closed loop having no sleeve ends.

For some applications, the sleeve has first and second sleeve ends, andplacing the sleeve includes introducing the flexible sleeve into a leftatrium while the first and the second sleeve ends are not coupled toeach other; and thereafter, in the left atrium, arranging the flexiblesleeve entirely around the annulus to form the closed loop.

For some applications, the annuloplasty ring further includes anelongated linking member, which is coupled to and disposed within thesleeve, and placing the flexible sleeve entirely around the annulusincludes placing the linking member along the anterior portion of theannulus.

For some applications, the linking member is configured as a spring. Forsome applications, the linking member is curved. For some applications,the linking member has a length of between 2 and 6 cm. For someapplications, the linking member includes metal. For some applications,the linking member is substantially longitudinally non-extensible.

For some applications:

the linking member includes a first coupling element,

the annuloplasty ring includes a second coupling element, which isconfigured to be coupleable to the first coupling element, and which iscoupled to the annuloplasty ring within 1.5 cm of one of the first andthe second sleeve ends, measured when the sleeve is fully longitudinallyextended,

the first and the second coupling elements are configured to provide anadjustable-length connection between the linking member and the one ofthe first and the second sleeve ends, and

placing the linking member along the anterior portion of the annulusincludes setting an effective length of the linking member whilecoupling the first and the second coupling elements together.

For some applications:

the linking member is disposed within a longitudinal portion of thesleeve,

the annuloplasty ring further includes an elongated radial-forceapplication element, which is disposed within the longitudinal portionof the sleeve, and

placing the linking member includes placing the elongated radial-forceapplication element along the anterior portion of the annulus, such thatthe elongated radial-force application element applies a force against awall of the longitudinal portion of the sleeve in at least oneradially-outward direction.

For some applications, placing the elongated radial-force applicationelement includes placing the elongated radial-force application elementalong the anterior portion of the annulus, such that the elongatedradial-force application element pushes the longitudinal portion of thesleeve against atrial tissue.

For some applications, the elongated radial-force application element isspringy.

For some applications, the elongated radial-force application elementincludes an inflatable element.

For some applications, the linking member is not configured as a spring.

For some applications, placing the linking member includes placing thelinking member such that the linking member does not apply any force tothe wall of the longitudinal portion of the sleeve.

For some applications, at least 90% of a length of the linking member isstraight when in a resting state.

For some applications, the linking member is substantiallylongitudinally non-extensible.

For some applications, the elongated radial-force application elementhas a length of between 2 and 6 cm, measured when the sleeve is fullylongitudinally extended.

For some applications:

the longitudinal portion of the sleeve is a first longitudinal portionof the sleeve,

-   -   the contracting assembly includes (a) a contracting mechanism,        and (b) a longitudinal contracting member, which is arranged        along a second longitudinal portion of the sleeve that is        entirely longitudinally distinct from the first longitudinal        portion of the sleeve, and    -   the elongated radial-force application element is disposed        entirely within the first longitudinal portion of the sleeve.

There is further provided, in accordance with an application of thepresent invention, a method including:

providing an annuloplasty ring, which includes (a) a flexible sleeve,and (b) a contracting assembly;

during a percutaneous transcatheter procedure, placing the flexiblesleeve entirely around an annulus of a mitral valve of a subject in aclosed loop;

fastening the sleeve to the annulus by coupling a plurality of tissueanchors to the annulus, with:

a first non-zero longitudinal density of the tissue anchors along aposterior portion of the annulus between left and right fibrous trigonesof the annulus, including the trigones, which density is equal to (a) anumber of the tissue anchors coupled to the annulus along the posteriorportion of the annulus divided by (b) a length of the posterior portionof the annulus, and

-   -   a second non-zero longitudinal density of the tissue anchors        along an anterior portion of the annulus between left and right        fibrous trigones of the annulus, not including the trigones,        which density is equal to (a) a number of the tissue anchors        coupled to the annulus along the anterior portion of the annulus        divided by (b) a length of the anterior portion of the annulus,        wherein the first longitudinal density is greater than the        second longitudinal density; and    -   thereafter, contracting a longitudinal portion of the sleeve.

For some applications, the contracting assembly further includes alongitudinal contracting member and a locking mechanism, and the methodfurther includes, after contracting the longitudinal portion of thesleeve, locking the longitudinal contracting member with respect to thecontracting assembly using the locking mechanism.

For some applications, contracting the longitudinal portion of thesleeve includes actuating the contracting assembly to contract thelongitudinal portion of the sleeve.

For some applications, the first longitudinal density is at least twicethe second longitudinal density.

For some applications, providing the annuloplasty ring includesproviding the annuloplasty ring in which the sleeve is shaped so as todefine an integrally closed loop having no sleeve ends.

For some applications, the sleeve has first and second sleeve ends, andplacing the flexible sleeve includes introducing the flexible sleeveinto a left atrium while the first and the second sleeve ends are notcoupled to each other; and thereafter, in the left atrium, arranging theflexible sleeve entirely around the annulus to form the closed loop.

For some applications, the annuloplasty ring further includes anelongated linking member, which is coupled to and disposed within thesleeve, and placing the flexible sleeve entirely around the annulusincludes placing the linking member along the anterior portion of theannulus.

For some applications, the linking member has a length of between 2 and6 cm.

For some applications, the linking member includes metal.

For some applications, the linking member is substantiallylongitudinally non-extensible.

For some applications:

the linking member includes a first coupling element,

the annuloplasty ring includes a second coupling element, which isconfigured to be coupleable to the first coupling element, and which iscoupled to the annuloplasty ring within 1.5 cm of one of the first andthe second sleeve ends, measured when the sleeve is fully longitudinallyextended,

the first and the second coupling elements are configured to provide anadjustable-length connection between the linking member and the one ofthe first and the second sleeve ends, and

placing the linking member along the anterior portion of the annulusincludes setting an effective length of the linking member whilecoupling the first and the second coupling elements together.

For some applications:

the linking member is disposed within a longitudinal portion of thesleeve,

the annuloplasty ring further includes an elongated radial-forceapplication element, which is disposed within the longitudinal portionof the sleeve, and

placing the linking member includes placing the elongated radial-forceapplication element along the anterior portion of the annulus, such thatthe elongated radial-force application element applies a force against awall of the longitudinal portion of the sleeve in at least oneradially-outward direction.

For some applications, placing the elongated radial-force applicationelement includes placing the elongated radial-force application elementalong the anterior portion of the annulus, such that the elongatedradial-force application element pushes the longitudinal portion of thesleeve against atrial tissue.

For some applications, the elongated radial-force application element isspringy.

For some applications, the elongated radial-force application elementincludes an inflatable element.

For some applications, the linking member is not configured as a spring.

For some applications, placing the linking member includes placing thelinking member such that the linking member does not apply any force tothe wall of the longitudinal portion of the sleeve.

For some applications, at least 90% of a length of the linking member isstraight when in a resting state.

For some applications, the linking member is substantiallylongitudinally non-extensible.

For some applications, the elongated radial-force application elementhas a length of between 2 and 6 cm, measured when the sleeve is fullylongitudinally extended.

For some applications:

the longitudinal portion of the sleeve is a first longitudinal portionof the sleeve,

the contracting assembly includes (a) a contracting mechanism, and (b) alongitudinal contracting member, which is arranged along a secondlongitudinal portion of the sleeve that is entirely longitudinallydistinct from the first longitudinal portion of the sleeve, and

the elongated radial-force application element is disposed entirelywithin the first longitudinal portion of the sleeve.

There is still further provided, in accordance with an application ofthe present invention, a method including:

providing an annuloplasty ring, which includes (a) a flexible sleeve,and (b) a contracting assembly;

during a percutaneous transcatheter procedure, placing the flexiblesleeve at least partially around an annulus of a mitral valve of asubject;

fastening the sleeve to the annulus by coupling a plurality of tissueanchors to the annulus, with:

a first longitudinal density of the tissue anchors along a lateralscallop (P1) of a posterior leaflet of the mitral valve, which densityis equal to (a) a number of the tissue anchors coupled to the annulusalong the lateral scallop (P1) divided by (b) a length of the lateralscallop (P1) along the annulus,

a second longitudinal density of the tissue anchors along a middlescallop (P2) of the posterior leaflet, which density is equal to (a) anumber of the tissue anchors coupled to the annulus along the middlescallop (P2) divided by (b) a length of the middle scallop (P2) alongthe annulus, and

a third longitudinal density of the tissue anchors along a medialscallop (P3) of the posterior leaflet, which density is equal to (a) anumber of the tissue anchors coupled to the annulus along the medialscallop (P3) divided by (b) a length of the medial scallop (P3) alongthe annulus, wherein the longitudinal densities are characterized by atleast one of the following: (a) the second longitudinal density is atleast twice the first longitudinal density, and (b) the secondlongitudinal density is at least twice the third longitudinal density;and

thereafter, contracting a longitudinal portion of the sleeve.

For some applications, the contracting assembly further includes alongitudinal contracting member and a locking mechanism, and the methodfurther includes, after contracting the longitudinal portion of thesleeve, locking the longitudinal contracting member with respect to thecontracting assembly using the locking mechanism.

For some applications, contracting the longitudinal portion of thesleeve includes actuating the contracting assembly to contract thelongitudinal portion of the sleeve.

For some applications, both (a) the second longitudinal density is atleast twice the first longitudinal density, and (b) the secondlongitudinal density is at least twice the third longitudinal density.

For some applications, the second longitudinal density is at least twicethe first longitudinal density.

For some applications, the second longitudinal density is at least twicethe third longitudinal density.

For some applications, coupling the plurality of tissue anchors to theannulus includes coupling at least 3 tissue anchors to the annulus alongthe middle scallop (P2).

For some applications, the tissue anchors have respective anchor heads,and coupling the plurality of tissue anchors to the annulus includescoupling the plurality of tissue anchors to the annulus such that, aftercontracting the longitudinal portion of the sleeve, each of the anchorheads of at least two of the tissue anchors coupled along the middlescallop (P2) touches at least one longitudinally-adjacent anchor head.

For some applications, coupling the plurality of tissue anchors to theannulus includes coupling the plurality of tissue anchors to the annulussuch that, before contracting the longitudinal portion of the sleeve,the anchor heads of the at least two of the tissue anchors do not touchthe at least one longitudinally-adjacent anchor head.

For some applications, coupling the plurality of tissue anchors to theannulus includes coupling the plurality of tissue anchors to the annulussuch that, after contracting the longitudinal portion of the sleeve,each of the anchor heads of at least three of the tissue anchors coupledalong the middle scallop (P2) touches at least onelongitudinally-adjacent anchor head.

For some applications, coupling the plurality of tissue anchors to theannulus includes coupling the plurality of tissue anchors to the annulussuch that, after contracting the longitudinal portion of the sleeve,none of the anchor heads of the tissue anchors coupled along the lateralscallop (P1) touches any of the other anchor heads of the tissueanchors.

For some applications, coupling the plurality of tissue anchors to theannulus includes coupling the plurality of tissue anchors to the annulussuch that, after contracting the longitudinal portion of the sleeve,none of the anchor heads of the tissue anchors coupled along the medialscallop (P3) touches any of the other anchor heads of the tissueanchors.

For some applications, coupling the plurality of tissue anchors to theannulus includes coupling the plurality of tissue anchors to the annulussuch that, after contracting the longitudinal portion of the sleeve, (a)none of the anchor heads of the tissue anchors coupled along the lateralscallop (P1) touches any of the other anchor heads of the tissueanchors, and (b) none of the anchor heads of the tissue anchors coupledalong the medial scallop (P3) touches any of the other anchor heads ofthe tissue anchors.

For some applications, coupling the plurality of tissue anchors to theannulus includes coupling the plurality of tissue anchors to the annulussuch that, after contracting the longitudinal portion of the sleeve, (a)a first number of the anchor heads of the tissue anchors coupled alongthe lateral scallop (P1) touch at least one longitudinally-adjacentanchor head, and (b) a second number of the anchors heads of the tissueanchors coupled along the middle scallop (P2) touch at least onelongitudinally-adjacent anchor head, the second number greater than thefirst number.

For some applications, coupling the plurality of tissue anchors to theannulus includes coupling the plurality of tissue anchors to the annulussuch that, after contracting the longitudinal portion of the sleeve, (a)a second number of the anchor heads of the tissue anchors coupled alongthe middle scallop (P2) touch at least one longitudinally-adjacentanchor head, and (b) a third number of the anchors heads of the tissueanchors coupled along the medial scallop (P3) touch at least onelongitudinally-adjacent anchor head, the second number greater than thethird number.

For some applications, coupling the plurality of tissue anchors to theannulus includes coupling the plurality of tissue anchors to the annulussuch that, after contracting the longitudinal portion of the sleeve:

a first number of the anchor heads of the tissue anchors coupled alongthe lateral scallop (P1) touch at least one longitudinally-adjacentanchor head,

a second number of the anchors heads of the tissue anchors coupled alongthe middle scallop (P2) touch at least one longitudinally-adjacentanchor head, and

a third number of the anchors heads of the tissue anchors coupled alongthe medial scallop (P3) touch at least one longitudinally-adjacentanchor head, the second number greater than the first number, and thesecond number greater than the third number.

For some applications, the sleeve has first and second sleeve ends, andplacing the sleeve includes introducing the flexible sleeve into a leftatrium while the first and the second sleeve ends are not coupled toeach other.

For some applications, placing the sleeve includes arranging the sleeveentirely around the annulus to form a closed loop, after introducing theflexible sleeve into the left atrium while the first and the secondsleeve ends are not coupled to each other.

For some applications, providing the annuloplasty ring includesproviding the annuloplasty ring in which the sleeve is shaped so as todefine an integrally closed loop having no sleeve ends.

There is additionally provided, in accordance with an application of thepresent invention, a method including:

providing an annuloplasty ring, which includes (a) a flexible sleeve and(b) a contracting assembly, which includes a longitudinal contractingmember;

during a percutaneous transcatheter procedure, placing the flexiblesleeve at least partially around an annulus of a mitral valve of asubject;

fastening the sleeve to the annulus by coupling a plurality of tissueanchors to the annulus, such that:

a first set of exactly three of the tissue anchors is disposed insuccession along the longitudinal contracting member with a firstdistance between longitudinal-end tissue anchors of the first set,measured along the annulus, and

a second set of exactly three of the tissue anchors is disposed insuccession along the longitudinal contracting member with a seconddistance between longitudinal-end tissue anchors of the second set,measured along the annulus, wherein the first distance equals at leasttwice the second distance, and wherein the first and the second sets donot share any common tissue anchors; and

thereafter, contracting a longitudinal portion of the sleeve by causingthe longitudinal contracting member to apply a contracting force to thelongitudinal portion of the sleeve.

For some applications, the contracting assembly further includes alocking mechanism, and the method further includes, after contractingthe longitudinal portion of the sleeve, locking the longitudinalcontracting member with respect to the contracting assembly using thelocking mechanism.

For some applications, contracting the longitudinal portion of thesleeve includes actuating the contracting assembly to contract thelongitudinal portion of the sleeve by causing the longitudinalcontracting member to apply the contracting force to the longitudinalportion of the sleeve.

There is yet additionally provided, in accordance with an application ofthe present invention, apparatus including an annuloplasty ring, whichincludes:

a flexible sleeve, having first and second sleeve ends;

a contracting assembly;

a first coupling element, which is coupled to the annuloplasty ringwithin 1.5 cm of the first sleeve end, measured when the sleeve is fullylongitudinally extended;

a second coupling element, which is configured to be coupleable to thefirst coupling element, and which is coupled to the annuloplasty ringwithin 1.5 cm of the second sleeve end, measured when the sleeve isfully longitudinally extended; and

an elongated springy element, which is disposed entirely within alongitudinal portion of the sleeve, wherein the springy element has (a)a first springy-element longitudinal end that is between 2 and 6 cm fromthe first sleeve end, measured when the sleeve is fully longitudinallyextended, and (b) a second springy-element longitudinal end that iswithin 1.5 cm of the first sleeve end, measured when the sleeve is fullylongitudinally extended,

wherein the springy element is configured to press the longitudinalportion of the sleeve against tissue.

For some applications, the contracting assembly further includes alongitudinal contracting member and a locking mechanism, which isconfigured to lock the longitudinal contracting member with respect tothe contracting assembly.

For some applications, the longitudinal portion of the sleeve is a firstlongitudinal portion of the sleeve, and the contracting assembly isconfigured to contract at least a portion of a second longitudinalportion of the sleeve, which second longitudinal portion is entirelylongitudinally distinct from the first longitudinal portion.

For some applications, a first end of the elongated springy elementincludes the first coupling element.

There is also provided, in accordance with an application of the presentinvention, a method including:

providing an annuloplasty ring, which includes (a) a flexible sleeve,having first and second sleeve ends, (b) a contracting assembly, (c) afirst coupling element, which is coupled to the annuloplasty ring within1.5 cm of the first sleeve end, measured when the sleeve is fullylongitudinally extended, (d) a second coupling element, which isconfigured to be coupleable to the first coupling element, and which iscoupled to the annuloplasty ring within 1.5 cm of the second sleeve end,measured when the sleeve is fully longitudinally extended, and (e) anelongated springy element, which is disposed entirely within a firstlongitudinal portion of the sleeve, wherein the springy element has (a)a first springy-element longitudinal end that is between 2 and 6 cm fromthe first sleeve end, measured when the sleeve is fully longitudinallyextended, and (b) a second springy-element longitudinal end that iswithin 1.5 cm of the first sleeve end, measured when the sleeve is fullylongitudinally extended;

during a percutaneous transcatheter procedure, placing the flexiblesleeve around a portion of an annulus of an atrioventricular valve of asubject, which portion includes a posterior portion of the annulus;

placing the first longitudinal portion of the sleeve along an anteriorportion of the annulus between fibrous trigones of the valve;

fastening the flexible sleeve to the portion of the annulus, such thatthe springy element presses the first longitudinal portion of the sleeveagainst tissue;

coupling the first and the second coupling elements together; and

contracting at least a portion of a second longitudinal portion of thesleeve, which second longitudinal portion is entirely longitudinallydistinct from the first longitudinal portion.

For some applications, the contracting assembly further includes alocking mechanism, and the method further includes, after contractingthe at least a portion of the second longitudinal portion of the sleeve,locking the longitudinal contracting member with respect to thecontracting assembly using the locking mechanism.

For some applications, contracting the at least a portion of the secondlongitudinal portion of the sleeve includes actuating the contractingassembly to contract the at least a portion of the second longitudinalportion of the sleeve.

For some applications, a first end of the elongated springy elementincludes the first coupling element.

There is further provided, in accordance with an application of thepresent invention, apparatus including an annuloplasty ring, whichincludes:

a flexible sleeve; and

an elongated radial-force application element, which (a) is disposedentirely within a longitudinal portion of the sleeve, (b) which has alength of no more than 6 cm, measured when the sleeve is fullylongitudinally extended, and (c) is configured to apply a force againsta wall of the longitudinal portion of the sleeve in at least oneradially-outward direction.

For some applications, the elongated radial-force application element isrotationally asymmetric and not helically symmetric.

For some applications, the elongated radial-force application element isconfigured to apply the force against the wall around less than 100% ofa perimeter of the wall.

For some applications, the elongated radial-force application element isconfigured to apply the force against the wall around less than 50% ofthe perimeter of the wall.

For some applications, the elongated radial-force application element isconfigured to apply the force with a variation of less than 20% along alength of the elongated radial-force application element.

For some applications, the sleeve has first and second sleeve ends.

For some applications, the annuloplasty ring further includes:

a first coupling element, which is coupled to the annuloplasty ringwithin 1.5 cm of the first sleeve end, measured when the sleeve is fullylongitudinally extended; and

a second coupling element, which is configured to be coupleable to thefirst coupling element, and which is coupled to the annuloplasty ringwithin 1.5 cm of the second sleeve end, measured when the sleeve isfully longitudinally extended.

For some applications, the elongated radial-force application elementhas (a) a first radial-force-application-element longitudinal end thatis between 2 and 6 cm from the first sleeve end, measured when thesleeve is fully longitudinally extended, and (b) a secondradial-force-application-element longitudinal end that is within 1.5 cmof the first sleeve end, measured when the sleeve is fullylongitudinally extended.

For some applications, the sleeve is shaped so as to define anintegrally closed loop having no sleeve ends.

For some applications:

the annuloplasty ring further includes a contracting assembly, whichincludes a housing that is fixed to the sleeve, and

the elongated radial-force application element has (a) a firstradial-force-application-element longitudinal end that is between 2 and6 cm from the housing, measured when the sleeve is fully longitudinallyextended, and (b) a second radial-force-application-element longitudinalend that is within 1.5 cm of the housing, measured when the sleeve isfully longitudinally extended.

For some applications, the elongated radial-force application element isconfigured to push the longitudinal portion of the sleeve against atrialtissue.

For some applications, the annuloplasty ring further includes asubstantially longitudinally non-extensible linking member, which hasfirst and second linking-member ends and is at least partially disposedwithin the longitudinal portion of the sleeve, and the secondlinking-member end includes the first coupling element.

For some applications, the linking member has a length of between 2 and6 cm.

For some applications, at least the longitudinal portion of the sleeveis substantially longitudinally non-extensible, and the first couplingelement is fixed to the wall of the sleeve within 1.5 cm of the firstsleeve end, measured when the sleeve is fully longitudinally extended.

For some applications, the elongated radial-force application elementincludes a springy element.

For some applications, where at least a portion of the springy elementis curved at least partially about an inner surface of the wall of thesleeve.

For some applications, at least a portion of the springy element isserpentine.

For some applications, the at least a portion of the springy element iscurved at least partially about the inner surface of the wall in asingle circumferential direction.

For some applications, at least a first portion of the springy elementis curved at least partially about the inner surface of the wall in afirst circumferential direction, and at least a second portion of thespringy element is curved at least partially about the inner surface ofthe wall in a second circumferential direction circumferentiallyopposite the first circumferential direction.

For some applications, at least a portion of the springy element isserpentine.

For some applications, springy element includes a coiled spring.

For some applications, the elongated radial-force application elementincludes an inflatable element.

For some applications,

the longitudinal portion of the sleeve is a first longitudinal portionof the sleeve, and

the annuloplasty ring further includes a longitudinal contractingmember, which is arranged only along a second longitudinal portion ofthe sleeve that is entirely longitudinally distinct from the firstlongitudinal portion of the sleeve.

For some applications, the annuloplasty ring further includes acontracting assembly, which includes the longitudinal contracting memberand a contracting mechanism.

For some applications, a first average internal diameter of the firstlongitudinal portion of the sleeve is greater than a second averageinternal diameter of the second longitudinal portion of the sleeve, whenboth the first and the second longitudinal portions are fully radiallyexpanded.

For some applications, the first longitudinal portion of the sleeve isradially elastic, and the second longitudinal portion of the sleeve issubstantially radially non-extensible.

For some applications, the first and the second longitudinal portions ofthe sleeve are substantially longitudinally non-extensible.

For some applications, the first and the second longitudinal portions ofthe sleeve have a same diameter when the first longitudinal portion isnot elastically stretched.

For some applications, the first and the second longitudinal portions ofthe sleeve are woven, and the first longitudinal portion of the sleeveis more loosely woven than the second longitudinal portion of thesleeve.

For some applications, the first longitudinal portion of the sleeve isradially stretchable, and the second longitudinal portion of the sleeveis substantially radially non-extensible.

For some applications, the annuloplasty ring further includes aplurality of tissue anchors, at least two of which are coupled to thesleeve at respective, different longitudinal sites alongside theelongated radial-force application member.

For some applications, the annuloplasty ring further includes acontracting assembly, which includes a contracting mechanism and alongitudinal contracting member, and the contracting mechanism is fixedto the sleeve within 1.5 cm of the second sleeve end, measured when thesleeve is fully longitudinally extended.

For some applications, the second coupling element is coupled to thecontracting mechanism.

For some applications, the longitudinal contracting member includes atleast one wire.

For some applications, the elongated radial-force application memberincludes metal.

For some applications, the metal includes Nitinol.

For some applications, at least one of the first and second couplingelements includes a hook.

For some applications, at least one of the first and second couplingelements includes a loop.

There is still further provided, in accordance with an application ofthe present invention, a method including:

providing an annuloplasty ring, which includes (a) a flexible sleeve and(b) an elongated radial-force application element, which is disposedentirely within a longitudinal portion of the sleeve;

during a percutaneous transcatheter procedure, placing the flexiblesleeve entirely around an annulus of an atrioventricular valve of asubject, such that the longitudinal portion of the sleeve is disposedalong an anterior portion of the annulus between fibrous trigones of thevalve; and

fastening the flexible sleeve at least to a posterior portion of theannulus, such that the elongated radial-force application elementapplies a force against the wall of the longitudinal portion of thesleeve in at least one radially-outward direction.

For some applications, the elongated radial-force application element isrotationally asymmetric and not helically symmetric.

For some applications, the elongated radial-force application element isconfigured to apply the force against the wall around less than 100% ofa perimeter of the wall.

For some applications, the elongated radial-force application element isconfigured to apply the force against the wall around less than 50% ofthe perimeter of the wall.

For some applications, the elongated radial-force application element isconfigured to apply the force with a variation of less than 20% along alength of the elongated radial-force application element.

For some applications, the flexible sleeve has first and second sleeveends, and placing the flexible sleeve includes introducing the flexiblesleeve into a left atrium while the first and the second sleeve ends arenot coupled to each other; and thereafter, in the left atrium, arrangingthe flexible sleeve entirely around the annulus to form the closed loop.

For some applications:

-   -   the annuloplasty ring further includes (a) a first coupling        element, which is coupled to the annuloplasty ring within 1.5 cm        of the first sleeve end, measured when the sleeve is fully        longitudinally extended, (b) a second coupling element, which is        configured to be coupleable to the first coupling element, and        which is coupled to the annuloplasty ring within 1.5 cm of the        second sleeve end, measured when the sleeve is fully        longitudinally extended, and    -   coupling the first and the second sleeve ends to each other to        form the closed loop includes coupling the first and the second        coupling elements together.

For some applications, the elongated radial-force application elementhas (a) a first radial-force-application-element longitudinal end thatis between 2 and 6 cm from the first sleeve end, measured when thesleeve is fully longitudinally extended, and (b) a secondradial-force-application-element longitudinal end that is within 1.5 cmof the first sleeve end, measured when the sleeve is fullylongitudinally extended,

For some applications, providing the annuloplasty ring includesproviding the annuloplasty ring in which the sleeve is shaped so as todefine an integrally closed loop having no sleeve ends.

For some applications:

the annuloplasty ring further includes a contracting assembly, whichincludes a housing that is fixed to the sleeve, and

the elongated radial-force application element has (a) a firstradial-force-application-element longitudinal end that is between 2 and6 cm from the housing, measured when the sleeve is fully longitudinallyextended, and (b) a second radial-force-application-element longitudinalend that is within 1.5 cm of the housing, measured when the sleeve isfully longitudinally extended.

For some applications, the elongated radial-force application elementincludes an inflatable element.

For some applications, placing the elongated radial-force applicationelement includes placing the elongated radial-force application elementalong the anterior portion of the annulus, such that the elongatedradial-force application element pushes the longitudinal portion of thesleeve against atrial tissue.

For some applications, the annuloplasty ring further includes asubstantially longitudinally non-extensible linking member, which hasfirst and second linking-member ends and is at least partially disposedwithin the longitudinal portion of the sleeve, and the secondlinking-member end includes the first coupling element.

For some applications, the linking member has a length of between 2 and6 cm.

For some applications, at least the longitudinal portion of the sleeveis substantially longitudinally non-extensible, and the first couplingelement is fixed to the wall of the sleeve within 1.5 cm of the firstsleeve end, measured when the sleeve is fully longitudinally extended.

For some applications, the elongated radial-force application elementincludes a springy element.

For some applications, placing the longitudinal portion of the sleeveincludes twisting the longitudinal portion of the sleeve after fasteningthe sleeve to the portion of the annulus.

For some applications, placing the longitudinal portion of the sleeveincludes twisting the springy element after fastening the sleeve to theportion of the annulus.

For some applications, where at least a portion of the springy elementis curved at least partially about an inner surface of the wall of thesleeve.

For some applications, at least a portion of the springy element isserpentine.

For some applications, the at least a portion of the springy element iscurved at least partially about the inner surface of the wall in asingle circumferential direction.

For some applications, at least a first portion of the springy elementis curved at least partially about the inner surface of the wall in afirst circumferential direction, and at least a second portion of thespringy element is curved at least partially about the inner surface ofthe wall in a second circumferential direction circumferentiallyopposite the first circumferential direction.

For some applications, at least a portion of the springy element isserpentine.

For some applications, springy element includes a coiled spring.

For some applications, the longitudinal portion of the sleeve is a firstlongitudinal portion, and the method further includes, after fasteningthe flexible sleeve at least to a posterior portion of the annulus,contracting a second longitudinal portion of the sleeve that is entirelylongitudinally distinct from the first longitudinal portion of thesleeve.

For some applications, the longitudinal portion of the sleeve is a firstlongitudinal portion of the sleeve, and the annuloplasty ring furtherincludes a longitudinal contracting member, which is arranged only alonga second longitudinal portion of the sleeve that is entirelylongitudinally distinct from the first longitudinal portion of thesleeve.

For some applications, the annuloplasty ring further includes acontracting assembly, which includes the longitudinal contracting memberand a contracting mechanism.

For some applications, a first average internal diameter of the firstlongitudinal portion of the sleeve is greater than a second averageinternal diameter of the second longitudinal portion of the sleeve, whenboth the first and the second longitudinal portions are fully radiallyexpanded.

For some applications, the first longitudinal portion of the sleeve isradially elastic, and the second longitudinal portion of the sleeve issubstantially radially non-extensible.

For some applications, the first and the second longitudinal portions ofthe sleeve are substantially longitudinally non-extensible.

For some applications, the first and the second longitudinal portions ofthe sleeve have a same diameter when the first longitudinal portion isnot elastically stretched.

For some applications, the first and the second longitudinal portions ofthe sleeve are woven, and the first longitudinal portion of the sleeveis more loosely woven than the second longitudinal portion of thesleeve.

For some applications, the first longitudinal portion of the sleeve isradially stretchable, and the second longitudinal portion of the sleeveis substantially radially non-extensible.

For some applications, the annuloplasty ring further includes acontracting assembly, which includes a contracting mechanism and alongitudinal contracting member, and the contracting mechanism is fixedto the sleeve within 30 mm of the second sleeve end, measured when thesleeve is fully longitudinally extended.

For some applications, the second coupling element is coupled to thecontracting mechanism.

For some applications, the longitudinal contracting member includes atleast one wire.

For some applications, the springy member includes metal.

For some applications, the metal includes Nitinol.

For some applications, at least one of the first and second couplingelements includes a hook.

For some applications, at least one of the first and second couplingelements includes a loop.

There is additionally provided, in accordance with an application of thepresent invention, apparatus including an implantable structure, whichincludes:

a flexible sleeve, having first and second sleeve ends;

a contracting assembly;

an elongated linking member, having a first and second linking memberends, which second linking member end includes a first coupling element,wherein the linking member is coupled to the sleeve such that (a) atleast a portion of the linking member is disposed within the sleeve, and(b) the first linking member end is longitudinally between the secondlinking member end and the first sleeve end, exclusive; and

a second coupling element, which is configured to be coupleable to thefirst coupling element, and which is coupled to the implantablestructure within 1.5 cm of the first sleeve end, measured when thesleeve is fully longitudinally extended.

For some applications, the contracting assembly is configured tolongitudinal contract the sleeve.

For some applications, the implantable structure further includes aplurality of tissue anchors, at least two of which are coupled to thesleeve at respective, different longitudinal sites alongside the linkingmember.

For some applications, the contracting assembly includes a contractingmechanism and a longitudinal contracting member, and the contractingmechanism is coupled to the sleeve within 1.5 cm of the first sleeveend.

For some applications, the second coupling element is coupled to thecontracting mechanism.

For some applications, the longitudinal contracting member includes atleast one wire.

For some applications, the linking member is configured as a spring.

For some applications, the linking member is curved.

For some applications, the linking member has a length of between 2 and6

cm.

For some applications, the linking member includes metal.

For some applications, the metal includes Nitinol.

For some applications, the linking member is substantiallylongitudinally non-extensible.

For some applications, at least 30% of a length of the linking member isdisposed within the sleeve.

For some applications, at least 75% of the length of the linking memberis disposed within the sleeve.

For some applications, the flexible sleeve is a first flexible sleeve,the implantable structure further includes a second flexible sleeve, andat least 20% of a length of the linking member is disposed within thesecond flexible sleeve.

For some applications, at least one of the first and second couplingelements includes a hook.

For some applications, at least one of the first and second couplingelements includes a loop.

For some applications, the at least a portion of the linking member isdisposed within a longitudinal portion of the sleeve, and theimplantable structure further includes an elongated springy element,which is disposed within the longitudinal portion of the sleeve, andwhich is configured to apply a force against a wall of the longitudinalportion of the sleeve in at least one radially-outward direction.

For some applications, the linking member is not configured as a spring.

For some applications, the linking member is configured not to apply anyforce to the wall of the longitudinal portion of the sleeve.

For some applications, at least 90% of a length of the linking member isstraight when in a resting state.

For some applications, the linking member is substantiallylongitudinally non-extensible.

For some applications, the springy element has a length of between 2 and6 cm, measured when the sleeve is fully longitudinally extended.

For some applications:

the longitudinal portion of the sleeve is a first longitudinal portionof the sleeve,

the contracting assembly includes (a) a contracting mechanism, and (b) alongitudinal contracting member, which is arranged only along a secondlongitudinal portion of the sleeve that is entirely longitudinallydistinct from the first longitudinal portion of the sleeve, and

the springy element is disposed entirely within the first longitudinalportion of the sleeve.

For some applications, the first and the second coupling elements areconfigured to provide an adjustable-length connection between thelinking member and the first sleeve end.

There is yet additionally provided, in accordance with an application ofthe present invention, a method including:

providing an implantable structure, which includes (a) a flexiblesleeve, having first and second sleeve ends, (b) a contracting assembly,(c) an elongated linking member, having a first and second linkingmember ends, which second linking member end includes a first couplingelement, wherein the linking member is coupled to the sleeve such that(i) at least a portion of the linking member is disposed within thesleeve, and (ii) the first linking member end is longitudinally betweenthe second linking member end and the first sleeve end, exclusive, and(d) a second coupling element, which is coupled to the implantablestructure within 1.5 cm of the first sleeve end, measured when thesleeve is fully longitudinally extended;

during a percutaneous transcatheter procedure, placing the flexiblesleeve around a portion of an annulus of an atrioventricular valve of asubject, which portion includes a posterior portion of the annulus;

placing the linking member along an anterior portion of the annulusbetween fibrous trigones of the valve;

fastening the flexible sleeve to the portion of the annulus;

coupling the first and the second coupling elements together; and

contracting a longitudinal portion of the sleeve.

For some applications, the contracting assembly further includes alocking mechanism, and the method further includes, after contractingthe longitudinal portion of the sleeve, locking the longitudinalcontracting member with respect to the contracting assembly using thelocking mechanism.

For some applications, contracting the second longitudinal portion ofthe sleeve includes actuating the contracting assembly to contract thelongitudinal portion of the sleeve.

For some applications, fastening includes fastening the sleeve to theannulus using a plurality of tissue anchors, including coupling at leasttwo of the anchors to the sleeve and tissue of the annulus atrespective, different longitudinal sites alongside the linking member.

For some applications, the contracting assembly includes a contractingmechanism and a longitudinal contracting member, and the contractingmechanism is coupled to the sleeve within 1.5 cm of the first sleeveend.

For some applications, the second coupling element is coupled to thecontracting mechanism.

For some applications, the linking member is configured as a spring.

For some applications, the linking member is curved.

For some applications, the linking member has a length of between 2 and6 cm.

For some applications, the linking member includes metal.

For some applications, the metal includes Nitinol.

For some applications, the linking member is substantiallylongitudinally non-extensible.

For some applications, at least 30% of a length of the linking member isdisposed within the sleeve.

For some applications, at least 75% of the length of the linking memberis disposed within the sleeve.

For some applications, the flexible sleeve is a first flexible sleeve,the implantable structure further includes a second flexible sleeve, andat least 20% of a length of the linking member is disposed within thesecond flexible sleeve.

For some applications, at least one of the first and second couplingelements includes a hook.

For some applications, at least one of the first and second couplingelements includes a loop.

For some applications:

the at least a portion of the linking member is disposed within alongitudinal portion of the sleeve,

the implantable structure further includes an elongated springy element,which is disposed within the longitudinal portion of the sleeve, and

placing the linking member includes placing the springy element alongthe anterior portion of the annulus, such that the springy elementapplies a force against a wall of the longitudinal portion of the sleevein at least one radially-outward direction.

For some applications, the linking member is not configured as a spring.

For some applications, placing the linking member includes placing thelinking member such that the linking member does not apply any force tothe wall of the longitudinal portion of the sleeve.

For some applications, at least 90% of a length of the linking member isstraight when in a resting state.

For some applications, the linking member is substantiallylongitudinally non-extensible.

For some applications, the springy element has a length of between 2 and6 cm, measured when the sleeve is fully longitudinally extended.

For some applications:

the longitudinal portion of the sleeve is a first longitudinal portionof the sleeve,

the contracting assembly includes (a) a contracting mechanism, and (b) alongitudinal contracting member, which is arranged only along a secondlongitudinal portion of the sleeve that is entirely longitudinallydistinct from the first longitudinal portion of the sleeve, and

the springy element is disposed entirely within the first longitudinalportion of the sleeve.

For some applications, the first and the second coupling elements areconfigured to provide an adjustable-length connection between thelinking member and the first sleeve end, and placing the linking memberalong the anterior portion of the annulus includes setting an effectivelength of the linking member while coupling the first and the secondcoupling elements together.

There is also provided, in accordance with an application of the presentinvention, apparatus including an annuloplasty system, which includes:

an implantable structure, which includes a flexible sleeve, having firstand second sleeve ends;

a linking bridge element, which includes first and second bridgecoupling interfaces, which are configured to be coupled to the sleeve inorder to link the first and the second sleeve ends via the linkingbridge element; and

first and second flexible longitudinal guide members, which (a) areremovably coupled to the sleeve within 1.5 cm of the first and thesecond sleeve ends, respectively, measured when the sleeve is fullylongitudinally extended, and (b) extend from the first and the secondsleeve ends, respectively, away from the sleeve, and (c) removably passthrough respective openings defined by the linking bridge member, so asto guide the first and the second bridge coupling interfaces tocorresponding locations on the sleeve.

For some applications, the respective openings defined by the linkingbridge member are defined by the first and the second bridge couplinginterfaces, respectively.

For some applications, the sleeve includes first and second sleevecoupling interfaces, to which the first and the second bridge couplinginterfaces are configured to be coupled, respectively.

For some applications, the first and the second sleeve couplinginterfaces are disposed within 1.5 cm of the first and the second sleeveends, respectively, measured when the sleeve is fully longitudinallyextended.

For some applications, the linking bridge element has a length ofbetween 1 and 5 cm.

For some applications, the implantable structure includes a longitudinalcontracting member, which is configured to longitudinally contract alongitudinal portion of the sleeve, and the first and the secondflexible longitudinal guide members are separate and distinct from thelongitudinal contracting member.

For some applications, wherein, when the first and the second flexiblelongitudinal guide members are removably coupled to the sleeve, thefirst and the second flexible longitudinal guide members do notlongitudinally overlap the longitudinal contracting member.

For some applications, wherein, when the first and the second flexiblelongitudinal guide members are removably coupled to the sleeve, noportion of either the first flexible longitudinal guide member or thesecond flexible longitudinal guide member is disposed more than 1.5 cmfrom the first and the second sleeve ends, respectively, measured whenthe sleeve is fully longitudinally extended.

For some applications, wherein, when the first and the second flexiblelongitudinal guide members are removably coupled to the sleeve, thefirst and the second flexible longitudinal guide members arecollectively disposed along less than 30% of a length of the sleeve,measured when the sleeve is fully longitudinally extended.

There is further provided, in accordance with an application of thepresent invention, a method including:

during a percutaneous transcatheter procedure, placing a flexible sleeveof an implantable structure partially around an annulus of a mitralvalve of a subject, such that first and second flexible longitudinalguide members, which are removably coupled to the sleeve, extend fromfirst and second sleeve ends of the sleeve, respectively, away from thesleeve, wherein the longitudinal guide members are removably coupled tothe sleeve within 1.5 cm of the first and the second sleeve ends of thesleeve, respectively, measured when the sleeve is fully longitudinallyextended;

advancing a linking bridge element into a left atrium of the subject,while the longitudinal guide members removably pass through respectiveopenings defined by the linking bridge member;

using the first and the second longitudinal guide members to guide firstand second bridge coupling interfaces of the linking bridge member tocorresponding locations on the sleeve; and

-   -   coupling the linking bridge member to the sleeve by coupling the        first and the second bridge coupling interfaces to the sleeve,        in order to link the first and the second sleeve ends via the        linking bridge element.

For some applications, the respective openings defined by the linkingbridge member are defined by the first and the second bridge couplinginterfaces, respectively.

For some applications, the sleeve includes first and second sleevecoupling interfaces, and coupling the first and the second bridgecoupling interfaces to the sleeve includes coupling the first and thesecond bridge coupling interfaces to the sleeve to the first and thesecond sleeve coupling interfaces, respectively.

For some applications, the first and the second sleeve couplinginterfaces are disposed within 1.5 cm of the first and the second sleeveends, respectively, measured when the sleeve is fully longitudinallyextended.

For some applications, the linking bridge element has a length ofbetween 1 and 5 cm.

For some applications:

the implantable structure includes a longitudinal contracting member,

the first and the second flexible longitudinal guide members areseparate and distinct from the longitudinal contracting member, and

the method further includes, after coupling the linking bridge member tothe sleeve, contracting a longitudinal portion of the sleeve by causingthe longitudinal contracting member to apply a contracting force to thelongitudinal portion of the sleeve.

For some applications, wherein, when the first and the second flexiblelongitudinal guide members are removably coupled to the sleeve, thefirst and the second flexible longitudinal guide members do notlongitudinally overlap the longitudinal contracting member.

For some applications, wherein, when the first and the second flexiblelongitudinal guide members are removably coupled to the sleeve, noportion of either the first flexible longitudinal guide member or thesecond flexible longitudinal guide member is disposed more than 1.5 cmfrom the first and the second sleeve ends, respectively, measured whenthe sleeve is fully longitudinally extended.

For some applications, wherein, when the first and the second flexiblelongitudinal guide members are removably coupled to the sleeve, thefirst and the second flexible longitudinal guide members arecollectively disposed along less than 30% of a length of the sleeve,measured when the sleeve is fully longitudinally extended.

There is still further provided, in accordance with an application ofthe present invention, apparatus including an annuloplasty system, whichincludes:

an implantable structure, which includes a flexible sleeve, having firstand second sleeve ends; and

first and second flexible longitudinal guide members, which (a) areremovably coupled to the sleeve within 1.5 cm of the first and thesecond sleeve ends, respectively, measured when the sleeve is fullylongitudinally extended, and (b) extend from the first and the secondsleeve ends, respectively, away from the sleeve.

For some applications, the implantable structure includes a longitudinalcontracting member, which is configured to longitudinally contract alongitudinal portion of the sleeve, and the first and the secondflexible longitudinal guide members are separate and distinct from thelongitudinal contracting member.

For some applications, wherein, when the first and the second flexiblelongitudinal guide members are removably coupled to the sleeve, thefirst and the second flexible longitudinal guide members do notlongitudinally overlap the longitudinal contracting member.

For some applications, wherein, when the first and the second flexiblelongitudinal guide members are removably coupled to the sleeve, noportion of either the first flexible longitudinal guide member or thesecond flexible longitudinal guide member is disposed more than 1.5 cmfrom the first and the second sleeve ends, respectively, measured whenthe sleeve is fully longitudinally extended.

For some applications, wherein, when the first and the second flexiblelongitudinal guide members are removably coupled to the sleeve, thefirst and the second flexible longitudinal guide members arecollectively disposed along less than 30% of a length of the sleeve,measured when the sleeve is fully longitudinally extended.

The present invention will be more fully understood from the followingdetailed description of applications thereof, taken together with thedrawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a system for repairing a dilatedatrioventricular valve, such as a mitral valve, in accordance with anapplication of the present invention;

FIGS. 2A-I are schematic illustrations of a procedure for implanting theimplantable structure of FIG. 1 to repair a mitral valve, in accordancewith an application of the present invention;

FIG. 3 is a schematic illustration of another configuration of theimplantable structure of FIG. 1, prior to implantation, in accordancewith an application of the present invention;

FIG. 4 is a schematic illustration of the implantable structure of FIG.3 after implantation around the annulus of a mitral valve, in accordancewith an application of the present invention;

FIG. 5 is a schematic illustration of a closed-loop configuration of theimplantable structure of FIG. 1, in accordance with an application ofthe present invention;

FIG. 6 is a schematic illustration of yet another configuration of theimplantable structure of FIG. 1, prior to implantation, in accordancewith an application of the present invention;

FIGS. 7A-B are schematic illustrations of the implantable structure ofFIG. 6 after implantation around the annulus of a mitral valve, inaccordance with respective applications of the present invention;

FIGS. 8A-D are schematic illustrations of coupling elements, inaccordance with respective applications of the present invention;

FIG. 9 is a schematic illustration of another configuration of theimplantable structure of FIG. 1, prior to implantation, furthercomprising an elongated radial-force application element, in accordancewith an application of the present invention;

FIG. 10 is a schematic illustration of the implantable structure of FIG.9 implanted around the mitral valve, in accordance with an applicationof the present invention;

FIGS. 11A-D are schematic illustrations of several configurations of theelongated radial-force application element of the implantable structureof FIGS. 9 and 10, in accordance with an application of the presentinvention;

FIG. 12 is a schematic illustration of another configuration of theelongated radial-force application element of the implantable structureof FIGS. 9 and 10, in accordance with an application of the presentinvention;

FIG. 13 is a schematic illustration of yet another configuration of theelongated radial-force application element of the implantable structureof FIGS. 9 and 10, in which the elongated radial-force applicationelement is helically symmetric, in accordance with an application of thepresent invention;

FIG. 14 is a schematic illustration of a configuration of the sleeve ofthe implantable structure of FIGS. 9 and 10, in accordance with anapplication of the present invention;

FIG. 15 is a schematic illustration of another configuration of theimplantable structure of FIGS. 9 and 10, in accordance with anapplication of the present invention;

FIGS. 16A-B are schematic illustrations of another configuration of theimplantable structure of FIGS. 9 and 10, in which the sleeve is shapedso as to define an integrally closed loop having no sleeve ends, inaccordance with an application of the present invention;

FIG. 17 is a schematic illustration of another configuration of theimplantable structure of FIG. 9 implanted around the mitral valve, inaccordance with an application of the present invention

FIGS. 18A and 18B are schematic illustrations of yet anotherconfiguration of the implantable structure of FIG. 1, prior toimplantation and upon implantation around the mitral valve,respectively, in accordance with an application of the presentinvention;

FIG. 19 is a schematic illustration of still another configuration ofthe implantable structure of FIG. 1 implanted around the mitral valve,in accordance with an application of the present invention;

FIG. 20 is a schematic illustration of another configuration of theimplantable structure of FIG. 1 implanted around the mitral valve, inaccordance with an application of the present invention;

FIG. 21 is a schematic illustration of still another configuration ofthe implantable structure of FIG. 1 implanted around the mitral valve,in accordance with an application of the present invention;

FIGS. 22A-D are schematic illustrations of another system for repairinga dilated atrioventricular valve, and a method for deploying the system,in accordance with an application of the present invention;

FIGS. 23A-B are schematic illustrations of another configuration of alinking bridge element of the system of FIGS. 22A-D, in accordance withan application of the present invention;

FIG. 24 is a schematic illustration of a contracting mechanism,disassembled to show a relationship among individual components of thecontracting mechanism, in accordance with an application of the presentinvention; and

FIGS. 25A-B and 26 are schematic illustrations of a valve prosthesisassembly, in accordance with respective applications of the presentinvention.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1 is a schematic illustration of a system 20 for repairing adilated atrioventricular valve, such as a mitral valve or a tricuspidvalve, in accordance with an application of the present invention.System 20 comprises an adjustable implantable structure 22, shown inFIG. 1 in a straight, relaxed, non-contracted state, and an anchordeployment manipulator 24 (shown in FIGS. 2G-H). For some applications,implantable structure 22 is configured to be deployed as an annuloplastyring, while for other applications, implantable structure 22 isconfigured to be deployed as a base ring to which a prosthetic valve iscoupled, such as described hereinbelow with reference to FIG. 25A-B or26. Implantable structure 22 comprises a flexible sleeve 26. Anchordeployment manipulator 24 is advanced into sleeve 26, as shown in FIGS.2G-H, and, from within the sleeve, deploys tissue anchors through a wallof the sleeve into cardiac tissue, thereby anchoring the ring around atleast a portion of the valve annulus. For some applications, anchordeployment manipulator is implemented using techniques described in USPatent Application Publication 2010/0280604, which is incorporatedherein by reference, with reference to FIGS. 2, 3, 4, 5A, 5B, 6A, 6B, 7,8, 13, and/or 20A-E thereof.

For some applications, implantable structure 22 comprises a partialannuloplasty ring. In these applications, sleeve 26 is configured to beplaced only partially around the valve annulus (i.e., to assume aC-shape), and, once anchored in place, to be contracted so as tocircumferentially tighten the valve annulus. For other applications,sleeve 26 is configured to be implanted entirely around the valveannulus in a closed loop, such as described hereinbelow with referenceto FIG. 4, 5, 7A-B, 10, 16A-B, 17 or 18B.

Implantable structure 22 further comprises a contracting assembly 40,which facilitates contracting of the implantable structure. Contractingassembly 40 typically comprises a contracting mechanism 28, and alongitudinal contracting member 30, which is coupled to contractingmechanism 28, extends along a portion of the sleeve, and is typicallyflexible. For example, contracting member 30 may comprise at least onewire. Contracting assembly 40 is configured to contract a longitudinalportion of sleeve 26, and is described in more detail hereinbelow. Inaddition, the implantable structure typically comprises a plurality oftissue anchors 38, typically between about 5 and about 20 anchors, suchas about 10 or about 16 anchors. In FIG. 1, anchors 38 are shown coupledto implantable structure 22, deployed through the wall of sleeve 26. Forsome applications, anchors 38 are configured as described with referenceto FIGS. 5A-C, 5D, 5E, 5F, 5G, 5H, and/or 5I in US Patent ApplicationPublication 2012/0330411, which is incorporated herein by reference,while for other applications, anchors 38 comprise tissue anchors knownin the art.

Flexible sleeve 26 may comprise a braided, knitted, or woven mesh or atubular structure comprising ePTFE. For some applications, the braidcomprises metal and fabric fibers. The metal fibers, which may compriseNitinol for example, may help define the shape of the sleeve, e.g., holdthe sleeve open to provide space for passage and manipulation ofdeployment manipulator 24 within the sleeve. The fabric fibers maypromote tissue growth into the braid. Typically, sleeve 26 issubstantially longitudinally non-extensible, i.e., a length thereof issubstantially constant, i.e., cannot be longitudinally stretched, undernormal usage conditions. Alternatively, the sleeve is somewhat elastic,which gives the sleeve a tendency to longitudinally contract, therebyhelping tighten the sleeve. For example, the sleeve may be bellows- oraccordion-shaped.

For some applications, the sleeve is configured to have a tendency toassume a straight shape when in its relaxed, non-contracted state. Thisstraightness may help the surgeon locate the next site for eachsubsequent anchor during the implantation procedure. For example,because the sleeve assumes a generally straight shape, the sleeve mayhelp provide an indication of distance between adjacent anchoring sites.For some applications, the sleeve is configured to have a controllablyvariable stiffness. For example, a somewhat stiff wire may be placed inthe sleeve to provide the stiffness, and subsequently be removed at theconclusion of the implantation procedure when the stiffness is no longeruseful.

For some applications, sleeve 26 comprises a plurality of radiopaquemarkers 39, which are positioned along the sleeve at respectivelongitudinal sites. The markers may provide an indication in aradiographic image (such as a fluoroscopy image) of how much of thesleeve has been deployed at any given point during an implantationprocedure, in order to enable setting a desired distance between anchors38 along the sleeve. For some applications, the markers comprise aradiopaque ink.

Typically, at least a portion (e.g., at least three, such as all) of thelongitudinal sites are longitudinally spaced at a constant interval.Typically, the longitudinal distance between the distal edges ofadjacent markers, and/or the distance between the proximal edges ofadjacent markers, is set equal to the desired distance between adjacentanchors. For example, the markers may comprise first, second, and thirdmarkers, which first and second markers are adjacent, and which secondand third markers are adjacent, and the distance between the proximaland/or distal edges of the first and second markers equal thecorresponding distance between the proximal and/or distal edges of thesecond and third markers. For example, the distance may be between 3 and15 mm, such as 6 mm, and the longitudinal length of each marker may bebetween 0.1 and 14 mm, such as 2 mm. (If, for example, the distance were6 mm and the length were 2 mm, the longitudinal gaps between adjacentmarkers would have lengths of 4 mm.)

Longitudinal contracting member 30 comprises a wire, a ribbon, a rope,or a band, which typically comprises a flexible and/or superelasticmaterial, e.g., nitinol, polyester, HDPE, stainless steel, or cobaltchrome. For some applications, the wire comprises a radiopaque material.For some applications, longitudinal contracting member 30 comprises abraided polyester suture (e.g., Ticron). For some applications,longitudinal contracting member 30 is coated withpolytetrafluoroethylene (PTFE). For some applications, contractingmember 30 comprises a plurality of wires that are intertwined to form arope structure. For some applications, implantable structure 22comprises a plurality of contracting members 30, which may extend alonggenerally the same longitudinal portion of sleeve 26, or alongrespective, different portions of sleeve 26 (e.g., as described withreference to FIG. 13 in above-mentioned US Patent ApplicationPublication 2012/0330411).

For some applications, contracting member 30 is positioned at leastpartially within a lumen of the sleeve 26, such as entirely within thelumen (as shown in FIGS. 1, 2H-I, 3, 4, 6, and 7A-B). For someapplications in which the contracting member is positioned partiallywithin the lumen, the contracting member is sewn into the wall of thesleeve, such that the contracting member is alternatingly inside andoutside of the sleeve along the length of the sleeve (configuration notshown). Optionally, sleeve 26 defines an internal channel within whichmember 30 is positioned (configuration not shown). Alternatively, thecontracting member is disposed outside the lumen of the sleeve, such asalongside an outer wall of the sleeve. For example, sleeve 26 may definean external channel within which contracting member 30 is positioned, orthe sleeve may comprise or be shaped so as to define external couplingelements, such as loops or rings (configuration not shown). For someapplications, contracting member 30 is positioned approximately oppositethe anchors.

For some applications of the present invention, contracting mechanism 28comprises a rotatable structure, such as a spool 46. The rotatablestructure is arranged such that rotation thereof applies a longitudinalcontracting force, thereby contracting at least a longitudinal portionof implantable structure 22. Typically, in these applications,contracting mechanism 28 further comprises a housing 44 in which therotatable structure, e.g., the spool, is positioned. Contracting member30 has first and second member ends, and a first member end portion,which extends from the first member end toward the second member endalong only a longitudinal portion of the contracting member. For someapplications, the first member end portion, e.g., the first member endof contracting member 30, is coupled to contracting mechanism 28, suchas the rotatable structure, e.g., the spool (alternatively, although thefirst member end portion is coupled to the contracting mechanism, thefirst member end protrudes beyond the contracting mechanism). Forexample, spool 46 may be shaped to provide a hole 42 or other couplingmechanism for coupling the first end of contracting member 30 to thespool, and thereby to contracting mechanism 28. Contracting assembly 40is arranged such that rotation of the spool winds a portion of thecontracting member around the spool. Alternatively, contracting member30 may comprise at least one wire (e.g., exactly one wire) that passesthrough a coupling mechanism of spool 46, in order to couple the wire tothe spool. The ends of the wire are brought together, and together serveas a second end 53 of contracting member 30. In this configuration,approximately the longitudinal center of the wire serves as the firstend of the contracting member.

Alternatively, contracting mechanism 28 may comprise a ratchetcontracting mechanism, which typically comprises a ratchet-couplinghousing. Contracting member 30 is shaped so as to define engagingstructures, such as grooves or teeth. Techniques may be used that aredescribed in International Application PCT/IL2009/000593, filed Jun. 15,2009, which published as PCT Publication WO 10/004546, and in U.S.application Ser. No. 12/996,954, which published as US PatentApplication Publication 2011/0166649, in the national stage thereof, allof which applications and publications are incorporated herein byreference.

Further alternatively, contracting mechanism 28 may comprise a housingor other structure (e.g., a ring or an eyelet) which is shaped so as todefine an opening therethrough. Contracting member 30 is drawn throughthe opening (such that the first member end protrudes beyond theopening), and, once a desired length has been achieved, is locked, suchas using a locking bead, or by crimping or knotting.

Contracting member 30 extends along less than the entire length ofsleeve 26. Contracting mechanism 28 (e.g., housing 44 thereof) isdisposed at a first site 34 of sleeve 26 that is a first longitudinaldistance D1 from a first end of the sleeve, either a proximal end 49 ofsleeve 26, as shown in FIG. 1, or a distal end 51 of sleeve 26, as shownin FIGS. 2G-I. (Longitudinal distance D1 is measured between the firstend of the sleeve and the portion of contracting mechanism 28 that isclosest to the first end.) For some applications, second end 53 ofcontracting member 30 is coupled to the sleeve at a second site 36 thatis a second longitudinal distance D2 from a second end of the sleeve,which second end is longitudinally opposite the first end of the sleeve.For applications in which contracting mechanism 28 comprises a rotatablestructure, rotation of the rotatable structure, such as spool 46,longitudinally contracts at least a portion of the sleeve, such as bywinding a portion of the contracting member around the spool, therebypulling the far end of the implantable structure toward the spool andshortening and tightening the implantable structure. Such rotation ofthe rotatable structure, or other actuation of contracting assembly 40,typically applies a longitudinal contracting force only between firstand second sites 34 and 36, which longitudinally contracts at least aportion, e.g. all, of the sleeve only between first and second sites 34and 36. (For example, the longitudinal force may longitudinally contractless than the entire sleeve between first and second sites 34 and 36 inapplications in which system 20 comprises coiled element 240, whichprovides a contraction-restricting portion of the sleeve, as describedhereinbelow with reference to FIGS. 10A-E and/or 11A-E inabove-mentioned US Patent Application Publication 2012/0330411.)Therefore, the portions of the sleeve beyond first and second sites 34and 36 (towards the ends of the sleeve) are not contracted bycontracting assembly 40.

Typically, contracting member 30 extends along (i.e., a distance alongthe sleeve between first and second sites 34 and 36 equals) no more than80% of the length of the sleeve, e.g., no more than 60% or no more than50% of the length. Typically, contracting member 30 extends along nomore than 80% of a circumference of the loop when the sleeve is placedaround the annulus (i.e., the total length of the loop less the lengthof any overlapping portion). Typically, contracting member 30 extendsalong (i.e., a distance along the sleeve between first and second sites34 and 36 equals) at least 20% of the length of the sleeve, e.g., atleast than 40% or at least than 50% of the length. Typically,contracting member 30 extends along at least 20% of the circumference ofthe loop when the sleeve is placed around the annulus, e.g., at least30% or at least 50%.

For some applications, first longitudinal distance D1, measured whensleeve 26 is in a straight, relaxed, non-contracted state, is at least 3mm, e.g., at least 5 mm, such as at least 9 mm, e.g., at least 14 mm; nogreater than 20 mm, such as no greater than 15 mm; and/or between 5 and20 mm, such as between 9 and 15 mm. Alternatively or additionally, forsome applications, second longitudinal distance D2, measured when sleeve26 is in a straight, relaxed, non-contracted state, is at least 3 mm,e.g., at least 5 mm, such as at least 9 mm, e.g., at least 14 mm; nogreater than 20 mm, such as no greater than 15 mm; and/or between 5 and20 mm, such as between 9 and 15 mm. Further alternatively oradditionally, first longitudinal distance D1, measured when sleeve 26 isin a straight, relaxed, non-contracted state, is no greater than 20%,such as no greater than 10% of a total length of the sleeve, measuredwhen sleeve 26 is in a straight, relaxed, non-contracted state. Furtheralternatively or additionally, second longitudinal distance D2, measuredwhen sleeve 26 is in a straight, relaxed, non-contracted state, is nogreater than 30%, such as no greater than 20%, e.g., no greater than 10%of the total length of the sleeve measured, when sleeve 26 is in astraight, relaxed, non-contracted state. For some applications, thetotal length of the sleeve, measured when the sleeve is in a straight,relaxed, non-contracted state is at least 5 cm, no more than 25 cm,and/or between 5 and 25 cm. For some applications in which the sleeve isimplanted in a closed loop, the total length of the sleeve is selectedto be between 1.3 and 1.4 times a circumference of the annulus, in orderto provide overlapping portion 114, described hereinbelow with referenceto FIGS. 3 and 4.

For some applications, at least one of tissue anchors 38 (e.g., exactlyone, at least two, exactly two, at least three, exactly three, or atleast four, or no more than four) is coupled to sleeve 26 longitudinallybetween contracting mechanism 28 (e.g., housing 44 thereof) and thefirst sleeve end (i.e., the end of the sleeve to which contractingmechanism 28 is closest), exclusive, and at least 3, such as at least 6,of tissue anchors 38 are coupled to the sleeve alongside contractingmember 30, longitudinally between first site 34 and second site 36(second member end 53), exclusive. (As used in the present application,including in the claims, “exclusive,” when used with respect to a rangeof locations, means excluding the endpoints of the range.)

Alternatively or additionally, for some applications, at least one oftissue anchors 38 (e.g., exactly one, at least two, exactly two, atleast three, exactly three, or at least four, or no more than four) iscoupled to sleeve 26 longitudinally between second site 36 (secondmember end 53) and the second sleeve end (i.e., the end of the sleeve towhich second member end 53 is closest), exclusive, and at least 3, suchas at least 6, of tissue anchors 38 are coupled to the sleeve alongsidecontracting member 30, longitudinally between first site 34 and secondsite 36 (second member end 53), exclusive.

In the exemplary configuration shown in FIG. 1, exactly two tissueanchors 38 are coupled to the sleeve longitudinally between thecontracting mechanism (e.g., the housing) (first site 34) and the firstsleeve end, exclusive, exactly two tissue anchors are coupled to thesleeve longitudinally between first site 34 and second site 36 (secondmember end 53), exclusive, and exactly six tissue anchors 38 are coupledto the sleeve alongside the contracting member, longitudinally betweenfirst site 34 and second site 36 (second member end 53), exclusive.

Providing the one or more anchors beyond first and second sites 34 and36 (i.e., beyond the contracting portion of contracting member 30)generally distributes force applied by contraction of contractingassembly 40 over these anchors. In contrast, in some configurations ofimplantable structure 22 in which anchors are not provided beyond firstand second sites 34 and 36, the force applied by the contractingassembly is applied predominantly to the single anchor nearest the firstend of the contracting member, and the single anchor nearest to secondend of the contracting member.

For some applications, anchors 38 are positioned along sleeve 26 with alongitudinal distance of between 4.5 and 9 mm, such as 6 mm, betweeneach pair of longitudinally-adjacent anchors.

It is noted that the anchors may be positioned as described above by asurgeon during an implantation procedure, such as described hereinbelowwith reference to FIGS. 2A-I, or the anchors may be prepositioned in thesleeve.

Reference is now made to FIGS. 2A-I, which are schematic illustrationsof a procedure for implanting implantable structure 22 to repair amitral valve 130, in accordance with an application of the presentinvention. The procedure is typically performed with the aid of imaging,such as fluoroscopy, transesophageal echo, and/or echocardiography.

The procedure typically begins by advancing a semi-rigid guidewire 102into a right atrium 120 of the patient, as shown in FIG. 2A.

As shown in FIG. 2B, guidewire 102 provides a guide for the subsequentadvancement of a sheath 104 therealong and into the right atrium. Oncesheath 104 has entered the right atrium, guidewire 102 is retracted fromthe patient's body. Sheath 104 typically comprises a 14-20 F sheath,although the size may be selected as appropriate for a given patient.Sheath 104 is advanced through vasculature into the right atrium using asuitable point of origin typically determined for a given patient. Forexample:

-   -   sheath 104 may be introduced into the femoral vein of the        patient, through an inferior vena cava 122, into right atrium        120, and into a left atrium 124 transseptally, typically through        the fossa ovalis;    -   sheath 104 may be introduced into the basilic vein, through the        subclavian vein to the superior vena cava, into right atrium        120, and into left atrium 124 transseptally, typically through        the fossa ovalis; or    -   sheath 104 may be introduced into the external jugular vein,        through the subclavian vein to the superior vena cava, into        right atrium 120, and into left atrium 124 transseptally,        typically through the fossa ovalis.

For some applications, sheath 104 is advanced through an inferior venacava 122 of the patient (as shown) and into right atrium 120 using asuitable point of origin typically determined for a given patient.

Sheath 104 is advanced distally until the sheath reaches the interatrialseptum.

As shown in FIG. 2D, a resilient needle 106 and a dilator (not shown)are advanced through sheath 104 and into the heart. In order to advancesheath 104 transseptally into left atrium 124, the dilator is advancedto the septum, and needle 106 is pushed from within the dilator and isallowed to puncture the septum to create an opening that facilitatespassage of the dilator and subsequently sheath 104 therethrough and intoleft atrium 124. The dilator is passed through the hole in the septumcreated by the needle. Typically, the dilator is shaped to define ahollow shaft for passage along needle 106, and the hollow shaft isshaped to define a tapered distal end. This tapered distal end is firstadvanced through the hole created by needle 106. The hole is enlargedwhen the gradually increasing diameter of the distal end of the dilatoris pushed through the hole in the septum.

The advancement of sheath 104 through the septum and into the leftatrium is followed by the extraction of the dilator and needle 106 fromwithin sheath 104, as shown in FIG. 2E.

As shown in FIG. 2F, implantable structure 22 (with anchor deploymentmanipulator 24 therein) is advanced through sheath 104 into left atrium124.

As shown in FIG. 2G, distal end 51 of sleeve 26 is positioned in avicinity of a left fibrous trigone 142 of an annulus 140 of mitral valve130. (It is noted that for clarity of illustration, distal end 51 ofsleeve 26 is shown schematically in the cross-sectional view of theheart, although left fibrous trigone 142 is in reality not located inthe shown cross-sectional plane, but rather out of the page closer tothe viewer.) Alternatively, the distal end is positioned in a vicinityof a right fibrous trigone 144 of the mitral valve (configuration notshown). Further alternatively, the distal end of the sleeve is notpositioned in the vicinity of either of the trigones, but is insteadpositioned elsewhere in a vicinity of the mitral valve, such as in avicinity of the anterior or posterior commissure. Still furtheralternatively, for some applications, the distal end is positioned alongan anterior portion of the annulus, such as described hereinbelow withreference to FIG. 4. For some applications, outer tube 66 of anchordeployment manipulator 24 is steerable, as is known in the catheter art,while for other applications, a separate steerable tube is provided,such as described in the above-mentioned '604 publication, withreference to FIG. 15 and FIG. 16 thereof. In either case, the steeringfunctionality typically allows the area near the distal end of thedeployment manipulator to be positioned with six degrees of freedom.Once positioned at the desired site near the selected trigone,deployment manipulator 24 deploys a first anchor 38 through the wall ofsleeve 26 into cardiac tissue near the trigone.

As shown in FIG. 2H, deployment manipulator 24 is repositioned alongannulus 140 to another site selected for deployment of a second anchor38. Typically, the first anchor is deployed most distally in the sleeve(generally at or within a few millimeters of the distal end of thesleeve), and each subsequent anchor is deployed more proximally, suchthat the sleeve is gradually pulled off (i.e., withdrawn from) thedeployment manipulator in a distal direction during the anchoringprocedure. The already-deployed first anchor 38 holds the anchored endof sleeve 26 in place, so that the sleeve is drawn from the site of thefirst anchor towards the site of the second anchor. Typically, as thesleeve is pulled off (i.e., withdrawn from) the deployment manipulator,the deployment manipulator is moved generally laterally along thecardiac tissue, as shown in FIG. 2H. Deployment manipulator 24 deploysthe second anchor through the wall of the sleeve into cardiac tissue atthe second site. Depending on the tension applied between the first andsecond anchor sites, the portion of sleeve 26 therebetween may remaintubular in shape, or may become flattened, which may help reduce anyinterference of the implantable structure with blood flow.

For some applications, in order to provide the second and subsequentanchors, anchor driver 68 is withdrawn from the subject's body viasheath 104 (typically while leaving outer tube 66 of the deploymentmanipulator in place in the sleeve), provided with an additional anchor,and then reintroduced into the subject's body and into the outer tube.Alternatively, the entire deployment manipulator, including the anchordriver, is removed from the body and subsequently reintroduced uponbeing provided with another anchor. Further alternatively, deploymentmanipulator 24 is configured to simultaneously hold a plurality ofanchors, and to deploy them one at a time at the selected sites.

As shown in FIG. 21, the deployment manipulator is repositioned alongthe annulus to additional sites, at which respective anchors aredeployed, until the last anchor is deployed in a vicinity of rightfibrous trigone 144 (or left fibrous trigone 142 if the anchoring beganat the right trigone), thereby fastening sleeve 26 and implantablestructure 22 to the annulus. Alternatively, the last anchor is notdeployed in the vicinity of a trigone, but is instead deployed elsewherein a vicinity of the mitral valve, such as in a vicinity of the anterioror posterior commissure.

For applications in which contracting mechanism 28 comprises spool 46, arotation tool is typically used to rotate spool 46 of contractingmechanism 28, in order to tighten implantable structure 22. For someapplications, the rotation tool is used that is described and shown inthe above-mentioned '604 publication, with reference to FIGS. 6A-B, 7,and 8 thereof. As described therein, contracting mechanism 28 compriseslongitudinal member 86 that is attached to the contracting mechanism andpasses out of the body of the subject, typically via sheath 104. Inorder to readily bring the rotation tool to a driving interface ofcontracting mechanism 28, the rotation tool is guided over longitudinalmember 86. For some applications, spool 46 is configured as described inthe '604 publication with reference to FIGS. 1-4, 6A-B, 7, and/or 8thereof.

Contracting assembly 40 typically comprises a locking mechanism thatlocks contracting member 30 with respect to contracting assembly 40,thereby preventing loosening (and typically tightening) of contractingmember 30. For some applications, spool 46 comprises the lockingmechanism that prevents rotation of the spool after contracting member30 has been tightened. For example, locking techniques may be used thatare described and shown in US Application Publication 2010/0161047,which is incorporated herein by reference, with reference to FIG. 4thereof, and/or with reference to FIGS. 6B, 7, and 8 of theabove-mentioned '604 publication. Alternatively, for some applications,contracting mechanism 28 is configured to tighten contracting member 30,crimp the contracting member to hold the contracting member taut, andsubsequently cut the excess length of the contracting member.

For some applications, a rotation handle is used to tighten theimplantable structure, such as described and shown in theabove-mentioned '604 publication, with reference to FIGS. 9A-C and 10A-Dthereof. As mentioned above, deploying the one or more anchors beyondthe contracting portion of contracting member 30 generally distributesforce applied by contraction of contracting assembly 40 over theseanchors.

For some applications, sleeve 26 is filled with a material (e.g.,polyester, polytetrafluoroethylene (PTFE), polyethylene terephthalate(PET), or expanded polytetrafluoroethylene (ePTFE)) after beingimplanted. The material is packed within at least a portion, e.g., 50%,75%, or 100%, of the lumen of sleeve 26. The filler material functionsto prevent (1) formation within the lumen of sleeve 26 of clots or (2)introduction of foreign material into the lumen which could obstruct thesliding movement of contracting member 30.

For some applications, proximal end 49 of sleeve 26 is closed uponcompletion of the implantation procedure. Alternatively, the proximalend of the sleeve may have a natural tendency to close when not heldopen by deployment manipulator 24.

For some applications, following initial contraction of implantablestructure 22 during the implantation procedure, the structure may befurther contracted or relaxed at a later time after the initialimplantation, such as between several weeks and several months after theinitial implantation. Using real-time monitoring and tactile feedback,optionally in combination with fluoroscopic imaging, a rotation tool oranchor driver of a deployment manipulator may be reintroduced into theheart and used to contract or relax implantable structure 22.

Reference is now made to FIGS. 3 and 4, which are schematicillustrations of another configuration of implantable structure 22, inaccordance with an application of the present invention. FIG. 3 showsimplantable structure 22 in a straight, relaxed, non-contracted state,prior to implantation. FIG. 4 shows the implantable structure afterimplantation around the annulus of mitral valve 130, in accordance withan application of the present invention.

In this configuration, sleeve 26 is implanted in a closed loop. Moreparticularly, a first portion 110 of sleeve 26 longitudinally extendsfrom the first sleeve end (i.e., the end of the sleeve to whichcontracting mechanism 28, e.g., housing 44 thereof, is closest) towardcontracting mechanism 28, e.g., housing 44 thereof (but typically doesnot extend all of the way to the contracting mechanism), and a secondportion 112 of the sleeve longitudinally extends from the second sleeveend (i.e., the end of the sleeve to which second member end 53 isclosest) toward second member end 53 (but typically does not extend allof the way to the second member end). As shown in FIG. 4, onceimplanted, sleeve 26 is arranged in a closed loop, such that first andsecond portions 110 and 112 of the sleeve together define alongitudinally overlapping portion 114 of the sleeve. The overlappingportion typically has a length of at least 2 mm (e.g., at least 5 mm),no more than 60 mm (e.g., no more than 50 mm), and/or between 2 mm(e.g., 5 mm) and 60 mm (e.g., 50 mm), and/or a length that is at least1% of a total length of the sleeve, no more than 40% of the total length(e.g., no more than 30%), and/or between 1% and 40% (e.g., 30%) of thetotal length of the sleeve, measured when the sleeve is in a straight,relaxed, non-contracted state.

For some applications, at least one of tissue anchors 38 (labeled as 38Ein FIGS. 3 and 4) penetrates both first and second portions 110 and 112of the sleeve at overlapping portion 114. Such a mutual anchor helpsensure that the first and second portions remain tightly coupledtogether and to the tissue, so that the sleeve retains its closed loopshape. For some applications in which tissue anchor 38E comprises acoupling head and a tissue coupling element, such as describedhereinbelow with reference to FIG. 5D, 5E, 5F, 5G, or 5I inabove-mentioned US Patent Application Publication 2012/0330411, thetissue coupling element penetrates both first and second portions 110and 112 of the sleeve at overlapping portion 114, and the coupling headis positioned within one of first and second portions 110 and 112 of thesleeve at the overlapping portion. For example, in the deploymentconfiguration shown in FIG. 4, the coupling head of anchor 38E ispositioned within second portion 112.

This configuration of implantable structure 22 may be implanted usingthe procedure described hereinabove with reference to FIGS. 2A-I, withthe following differences. Unlike in the deployment shown in FIGS. 2G-I,in this configuration sleeve 26 is deployed as a closed band around theentire annulus of the native valve, including an anterior portion 116 ofthe annulus (on the aortic side of the valve) between fibrous trigones142 and 144. Typically, both first and second portions 110 and 112 ofsleeve 26 (and thus overlapping portion 114) are positioned alonganterior portion 116 of the annulus.

For some applications, during the implantation procedure, the firstsleeve end (i.e., the end of the sleeve to which contracting mechanism28, e.g., housing 44 thereof, is closest) is placed along at least aportion of anterior portion 116 and first portion 110 is extended alongthis portion. At least one anchor 38D is deployed through the wall offirst portion 110 of sleeve 26 into cardiac tissue at the anteriorportion of the annulus. Additional anchors 38A and/or 38C are deployedthrough the wall of the sleeve around the non-anterior remainder of theannulus, including the posterior portion thereof, as describedhereinabove with reference to FIG. 2H. (Anchors 38C, if provided, aredeployed beyond the ends of the contracting portion of contractingmember 30, while anchors 38A are deployed along the portion of thesleeve including the contracting portion of the contracting member.)

A portion of the sleeve is placed on at least a portion of anteriorportion 116 of the annulus, and, typically, one or more anchors 38B aredeployed through the wall of the sleeve into tissue at the anteriorportion of the annulus.

The sleeve is further extended around the annulus until second portion112 overlaps with previously-deployed first portion 110 at overlappingportion 114, forming a complete ring. At least one anchor 38E isdeployed from within second portion 112 through the wall of the sleeveand into the cardiac tissue, typically at anterior portion 116 of theannulus, or at a portion of the annulus near anterior portion 116.Typically, anchor 38E is deployed such that it additionally passesthrough previously-deployed first portion 110 (passing through the wallof first portion 110 twice). (Optionally, anchors 38B and/or 38E are ofa different configuration than anchors 38A, 38C, and/or 38D, such asdescribed with reference to FIGS. 5A-I in above-mentioned US PatentApplication Publication 2012/0330411; anchors 38B and 38E may be of thesame configuration as one another, or of different configurations.)

Alternatively, the second sleeve end (i.e., the end of the sleeve towhich second member end 53 is closest) is first placed at leastpartially along anterior portion 116, in which case second portion 112is deployed before first portion 110, and anchor 38E is deployed fromwithin first portion 110.

The sleeve may be deployed in either a clockwise direction or acounterclockwise direction, as viewed from the atrium.

Contracting assembly 40 is actuated, e.g., the rotatable structure ofcontracting mechanism 28 is rotated, in order to tighten implantablestructure 22, as described hereinabove with reference to FIG. 21.Typically, contracting member 30 does not extend along the portion ofsleeve 26 deployed along anterior portion 116 of the annulus, and thusdoes not extend along first portion 110, second portion 112, oroverlapping portion 114 of sleeve 26. The portion of the sleeve deployedalong anterior portion 116 of the annulus (between the trigones) is thusnon-contractible. For some applications, contracting member 30 ispositioned along a non-anterior portion of the annulus, whichnon-anterior portion does not reach either of the fibrous trigones,e.g., does not reach within 5 mm of either of the trigones. Tighteningof implantable structure 22 therefore tightens at least a portion of theposterior portion of the annulus, while preserving the length ofanterior portion 116 of the annulus. (The anterior portion of theannulus should generally not be contracted because its tissue is part ofthe skeleton of the heart.) However, the portion of the sleeve deployedalong the anterior portion of the annulus prevents dilation of theanterior annulus, because the sleeve is anchored at both ends of theanterior annulus, and, as mentioned above, the sleeve typicallycomprises a longitudinally non-extensible material. This deploymentconfiguration may help prevent long-term resizing of the anteriorannulus, which sometimes occurs after implantation of partialannuloplasty rings, such as C-bands.

For some applications, the non-contractible portion of sleeve 26 (theportion without contracting member 30) extends somewhat beyond one orboth of trigones 142 or 144 (in the posterior direction, away fromanterior portion 116 of the annulus), such as up to 20 mm, such as up to10 mm. In general, since the non-contractible portions of the sleeve arepreset, the surgeon is able to decide during the implantation procedurethe lengths of the anterior non-contractible area and the posteriorcontractible area, by selecting the length of overlapping portion 114.The greater the length of overlapping portion 114, the greater therelative length of the posterior contractible portion, and the lesserthe relative length of the non-contractible portion.

For some applications, at least one anchor 38C is coupled to cardiactissue on the posterior side of right fibrous trigone 144, between thetrigone and the end of contracting member 30. Similarly, at least oneanchor 38C may be coupled to cardiac tissue on the posterior side ofleft fibrous trigone 142, between the trigone and the other end ofcontracting member 30 (which, for some applications, is coupled tocontracting mechanism 28, as shown in FIG. 4).

For some applications, at least one (either one or both) of first andsecond longitudinal distances D1 and D2 (described hereinabove withreference to FIG. 1), taken separately, is greater than 40 mm, such asgreater than 60 mm. This sleeve portion(s) beyond the contractingportion of contracting member 30 provide the non-contractible portion ofthe sleeve positioned along anterior portion 116 of the annulus, and,optionally, the non-contractible portion(s) that extend beyond theanterior portion.

Reference is still made to FIGS. 3 and 4. For some applications, anchors38 deployed along anterior portion 116 of the annulus (between thetrigones) are of a different configuration from anchors 38 deployedalong the remainder of the annulus (including the posterior portion ofthe annulus). Unlike the remainder of the annulus, anterior portion 116does not comprise muscular or fibrous tissue, but rather thinner aortictissue (typically the anchors positioned along anterior portion 116enter the aorta below the aortic leaflets). The anchors that aredeployed along the remainder of the annulus are configured for strongcoupling to the thicker and stronger fibrous tissue of these portions ofthe annulus. Such anchors may be inappropriate for coupling to anteriorportion 116. Anchors 38 are thus provided that are particularlyconfigured for coupling to anterior portion 116. For example, differentconfigurations of anchors 38 are described with reference to FIGS. 5A-Iin above-mentioned US Patent Application Publication 2012/0330411.

For these applications, anchors 38 include a plurality of first tissueanchors of a first configuration, and a plurality of second tissueanchors of a second configuration different from the firstconfiguration. (The first tissue anchors are labeled 38A and 38C in FIG.4, and for the sake of brevity, are referenced as 38A hereinbelow. Thesecond tissue anchors are labeled 38B, 38D, and 38E in FIG. 4, and forthe save of brevity, are referenced as 38B hereinbelow.) For someapplications, implantable structure 22 comprises more first tissueanchors 38A than second tissue anchors 38B, e.g., at least twice as manyfirst tissue anchors as second tissue anchors.

For these applications, sleeve 26 is typically arranged as a loop. Forexample, as described hereinabove with reference to FIG. 4, the sleevemay be shaped so as to define first and second sleeve ends, which arecoupled to each other (optionally, with overlapping portion 114) to formthe loop. Alternatively, as described hereinbelow with reference to FIG.6, the sleeve may be shaped so as to define an integrally closed loophaving no sleeve ends. First tissue anchors 38A are coupled to sleeve 26at intervals along a first longitudinally-contiguous portion of theloop, and second tissue anchors 38B are coupled to sleeve 26 atintervals along a second longitudinally-contiguous portion of the loopdifferent from the first longitudinally-contiguous portion. The secondportion of the loop is deployed along anterior portion 116 of theannulus, and the first portion of the loop is deployed along at least aportion of the remainder of the annulus (including the posterior portionof the annulus).

Reference is made to FIG. 5, which is a schematic illustration of analternative closed-loop configuration of implantable structure 22, inaccordance with an application of the present invention. In thisconfiguration, flexible sleeve 26 is shaped so as to define anintegrally closed loop having no sleeve ends. For some applications,anchors 38 deployed along anterior portion 116 of the annulus are of adifferent configuration from anchors 38 deployed along the remainder ofthe annulus, as described hereinabove with reference to FIGS. 3-4. Theanchors may be configured as described with reference to FIGS. 5A-I inabove-mentioned US Patent Application Publication 2012/0330411.

Typically, contracting member 30 does not extend along the portion ofsleeve 26 deployed along anterior portion 116 of the annulus. Theportion of the sleeve deployed along anterior portion 116 of the annulus(between the trigones) is thus non-contractible. Tightening ofimplantable structure 22 therefore tightens at least a portion of theposterior portion of the annulus, while preserving the length ofanterior portion 116 of the annulus. (The anterior portion of theannulus should generally not be contracted because its tissue is part ofthe skeleton of the heart.) However, the portion of the sleeve deployedalong the anterior portion of the annulus prevents dilation of theanterior annulus, because the sleeve is anchored at both ends of theanterior annulus, and, as mentioned above, the sleeve typicallycomprises a longitudinally non-extensible material. This deploymentconfiguration may help prevent long-term resizing of the anteriorannulus, which sometimes occurs after implantation of partialannuloplasty rings, such as C-bands.

For some applications, the non-contractible portion of sleeve 26 (theportion without contracting member 30) extends somewhat beyond one orboth of trigones 142 or 144 (in the posterior direction, away fromanterior portion 116 of the annulus), such as up to 20 mm, such as up to10 mm.

For some applications, at least one anchor 38 is coupled to cardiactissue on the posterior side of right fibrous trigone 144, between thetrigone and the end of contracting member 30. Similarly, at least oneanchor 38 may be coupled to cardiac tissue on the posterior side of leftfibrous trigone 142, between the trigone and the other end ofcontracting member 30 (which, for some applications, is coupled tocontracting mechanism 28, as shown in FIG. 5).

Reference is now made to FIGS. 6 and 7A-B, which are schematicillustrations of another configuration of implantable structure 22, inaccordance with an application of the present invention. FIG. 6 showsimplantable structure 22 in a relaxed, non-contracted state, and FIGS.7A-B shows the implantable structure implanted around mitral valve 130.This configuration of implantable structure 22 is generally similar tothe configuration described hereinabove with reference to FIG. 1, exceptas follows. In this configuration, implantable structure 22 furthercomprises an elongated linking member 250, which is positioned at leastpartially along anterior portion 116 of the annulus, so as to join theends of implantable structure 22 in a complete loop. Over time afterimplantation, linking member 250 becomes fixed to anterior portion 116of the annulus, thereby helping prevent long-term dilation of theanterior annulus. Typically, at least a portion (e.g., at least 30%,such as at least 75% or at least 90%) of a length of linking member 250is disposed within and covered by sleeve 26, into and/or over whichfibrous tissue grows over time, helping anchor the linking member totissue of the anterior annulus. Alternatively or additionally, aseparate flexible sleeve or a coating (e.g., a polymeric coating) may beprovided that covers at least 20%, e.g., between 20% and 80%, of thelinking member. Typically, in the configuration of implantable structure22 shown in FIGS. 6 and 7A-B, none of anchors 38 is coupled to anteriorportion 116 of the annulus. For some applications, as shown in FIG. 7A,implantable structure 22 is implanted with contracting mechanism 28disposed near left fibrous trigone 142, while for other applications, asshown in FIG. 7B, implantable structure 22 is implanted with contractingmechanism 28 disposed near right fibrous trigone 144. This latterarrangement may facilitate placement of the first-deployed, distal-mostanchor 38 near right fibrous trigone 144, which is above the fossaovalis, and the linking of first and second coupling elements 256 and260 later in the implantation procedure.

Linking member 250 has first and second linking member ends 252 and 254.Second linking member end 254 comprises (e.g., is shaped so as todefine, or is fixed to) a first coupling element 256. First linkingmember end 252 is disposed longitudinally between second linking memberend 254 and a first sleeve end (either proximal end 49, as shown, ordistal end 51, not shown), exclusive. Second linking member end 254either protrudes from the second end of the sleeve, or is recessedwithin the second end of the sleeve (as shown, the second end of thesleeve is distal end 51). A longitudinal portion of linking member 250in a vicinity of first linking member end 252 is coupled to the sleeve.For example, the portion may be threaded through the fabric of thesleeve, and/or sewn (e.g., sutured) to the fabric of the sleeve to holdthe linking member in place during deployment, and the linking membermay be held in place after implantation by one or more of anchors 38,such as two or more anchors 38F. Optionally, the linking member is notinitially coupled to the sleeve, but is instead held in place by adelivery tool during the implantation procedure, until being coupled tothe sleeve by one or more of the anchors, for example. The coupledlongitudinal portion may have a length of between 2 and 10 mm, andoptionally includes first linking member end 252 of the linking member.

Implantable structure 22 further comprises a second coupling element260, which is configured to be coupleable to first coupling element 256.Second coupling element 260 typically is coupled to implantablestructure 22 within 1.5 cm of the first end of sleeve 26 (opposite theend mentioned above near which first linking member end 252 is fixed),measured when the sleeve is fully longitudinally extended. As mentionedabove, in the configuration shown in FIGS. 6 and 7A-B, this first end isproximal end 49.

For some applications, such as shown in FIGS. 6 and 7A-B, contractingmechanism 28 (e.g., housing 44 thereof) is disposed along sleeve 26within 30 mm, such as within 15 mm, of the first sleeve end (i.e., thesame end of the sleeve near which the second coupling element iscoupled), measured when sleeve 26 is fully longitudinally extended. Forexample, contracting mechanism 28 (e.g., housing 44 thereof) may befixed at the first sleeve end. Alternatively, for some applications,contracting mechanism 28 (e.g., housing 44 thereof) is fixed at least 5mm from the first sleeve end, e.g., between 5 and 30 mm, such as between5 and 15 mm, from the first sleeve end. Second coupling element 260 maybe coupled to contracting mechanism 28 (e.g., to housing 44).Alternatively, second coupling element 260 may be otherwise coupled tosleeve 26 (such as directly coupled), in which case contractingmechanism 28, e.g., housing 44 thereof, may be coupled to sleeve 26 at agreater longitudinal distance from the end of the sleeve, and one ormore of anchors 38 may be coupled to the sleeve longitudinally betweenthe contracting mechanism and the sleeve end, such as describedhereinabove with reference to FIGS. 1, 2A-I, 3, and 4.

Typically, linking member 250 is substantially longitudinallynon-extensible, i.e., its length is fixed. Typically, linking member 250comprises metal, such as Nitinol or stainless steel. For someapplications, the linking member has a length of at least 2 cm, no morethan 6 cm, and/or between 2 and 6 cm.

For some applications, the linking member is configured as a spring,which is typically curved, so as to be elastic in a radial direction,i.e., to be compressible like a bow or deflected beam. In theseapplications, the linking member is oriented such that it is pressed byelasticity against the anterior portion of the mitral annulus, i.e., theouter wall of the aorta, thereby holding the sleeve covering the linkingmember against the aortic wall.

For some applications, at least two of tissue anchors 38 are coupled tosleeve 26 at respective, different longitudinal sites alongside linkingmember 250, within 6 cm of first linking member end 252, such as within2 to 6 cm of the first end. These tissue anchors may help set the properdirection of curvature of the linking member, for applications in whichthe linking member is curved.

Reference is made to FIGS. 8A-D, which are schematic illustrations ofcoupling elements 256 and 260, in accordance with respectiveapplications of the present invention. For some applications, at leastone of first and second coupling elements 256 and 260 comprises a hook270. Alternatively or additionally, for some applications, at least oneof the first and second coupling elements comprises a loop 272. In theconfiguration shown in FIG. 8A (and FIGS. 6 and 7A-B), first couplingelement 256 comprises hook 270, and second coupling element 260comprises a loop 272. In the configuration shown in FIG. 8B, both firstand second coupling elements 256 and 260 comprises respective loops 272,and the coupling elements are coupled together such as by placing one ofanchors 38 through both loops and into cardiac tissue.

For some applications, first and second coupling elements 256 and 260are configured to provide an adjustable-length connection betweenlinking member 250 and the first end of sleeve. Such anadjustable-length connection allows the effective length of linkingmember 250 to be set during the implantation procedure in order toaccommodate variations in individual patient anatomy. For someapplications, such as shown in FIG. 8C, first coupling element 256comprises a flexible elongate member 274, which comprises a plurality ofprotrusions 276 distributed along a portion of flexible elongate member274. Flexible elongate member 274 is drawn through a loop defined bysecond coupling element 260 until a desired length of linking member 250is achieved; one of the protrusions prevents loosening. Alternatively,second coupling element 260 comprises flexible elongate member 274(having protrusions 276), and first coupling element 256 defines theloop through which flexible elongate member 274 is drawn (configurationnot shown). For some applications, such as shown in FIG. 8D, firstcoupling element 256 comprises a plurality of loops 272, arrangedlongitudinally (each loop is connected to an adjacent loop, eitherdirectly or such as by a short length of wire), and second couplingelement 260 comprises a single loop 272. The healthcare professionalselects which of loops 272 of first coupling element 256 to couple withthe single loop 272 of second coupling element 260, in order to set thelength of linking member 250. Alternatively, second coupling element 260comprises the plurality of loops 272, and first coupling element 256comprises the single loop 272, or both first and second couplingelements 256 and 260 comprise pluralities of loops (configurations notshown).

Reference is now made to FIGS. 9-17, which are schematic illustrationsof additional configurations of implantable structure 22, in accordancewith respective applications of the present invention. FIGS. 9 and12-16B show implantable structure 22 (which typically comprises anannuloplasty ring) in a relaxed, non-contracted state. FIGS. 11A-D showseveral configurations of an elongated radial-force application element482, labeled with reference numerals 482A, 482B, 482C, and 482D,respectively. These configurations of implantable structure 22 aregenerally similar to the configuration described hereinabove withreference to FIG. 1, except as follows, and may incorporate any of thefeatures of the configuration described hereinabove with reference toFIG. 1, mutatis mutandis.

FIG. 10 shows implantable structure 22 implanted around mitral valve130, before a longitudinal portion of sleeve 26 has been contracted. Forsome applications, as shown in FIG. 10, implantable structure 22 isimplanted with contracting mechanism 28 disposed near left fibroustrigone 142, while for other applications (not shown, but similar to thearrangement shown in FIG. 7B), implantable structure 22 is implantedwith contracting mechanism 28 disposed near right fibrous trigone 144.This latter arrangement may facilitate placement of the first-deployed,distal-most anchor 38 near right fibrous trigone 144, which is above thefossa ovalis, and the linking of first and second coupling elements 456and 260 later in the implantation procedure, for applications in whichthese coupling elements are provided, such as described hereinbelow.

In these configurations, implantable structure 22 further compriseselongated radial-force application element 482, which is disposedentirely within a first longitudinal portion of sleeve 26. Elongatedradial-force application element 482 is configured to apply a forceagainst a wall of the first longitudinal portion of sleeve 26 in atleast one radially-outward direction. The applied force pushes the firstlongitudinal portion of sleeve 26 against tissue of the left atrium,such as against tissue of the annulus and/or the atrial wall, so as toinhibit blood flow between sleeve 26 and the tissue. It is generallydesirable to inhibit blood flow between sleeve 26 and the annulus onanterior side, to avoid creating turbulence.

For some applications, elongated radial-force application element 482 isconfigured to apply a force against the wall of at least 20 gram-force,no more than 1 kg-force, and/or between 20 gram-force and 1 kg-force,such as at least 50 gram-force, no more than 500 gram-force (e.g., nomore than 300 gram-force), and/or between 50 gram-force and 500gram-force (e.g., between 50 gram-force and 300 gram-force). For someapplications, elongated radial-force application element 482 isconfigured to apply the force generally constantly along the length ofelongated radial-force application element 482, e.g., with a variationof less than 20% along the length.

When implanting implantable structure 22, elongated radial-forceapplication element 482 is placed along anterior portion 116 of theannulus, between fibrous trigones 142 and 144 (a portion of elongatedradial-force application element 482 may extend beyond one or both ofthe trigones, such as for coupling to anchors 38F, as describedhereinbelow). If, upon initial placement, radial-force applicationelement 482 does not apply the force against the wall of sleeve 26 inthe desired radial direction (e.g., in the direction of the atrialwall), the healthcare professional may rotate the radial-forceapplication element 482 within the sleeve, and/or rotate (e.g., twist)the first longitudinal portion of sleeve 26. Typically, longitudinalportion 480 extends along at least 20 mm of anterior portion 116 of theannulus, and/or along at least 20%, no more than 100%, and/or between20% and 100% of anterior portion 116 of the annulus, such as at least30%, no more than 60%, and/or between 30% and 60% of anterior portion116. Typically, in the configuration of implantable structure 22 shownin FIGS. 9-10 and 12-16B, none of anchors 38 is coupled to anteriorportion 116 of the annulus.

Typically, elongated radial-force application element 482 has a lengthof no more than 6 cm, measured when sleeve 26 is fully longitudinallyextended.

For some applications, elongated radial-force application element 482 isrotationally asymmetric and not helically symmetric, such as shown inFIGS. 9-12 and 14-16B.

For some applications, such as shown in FIGS. 9-16B, elongatedradial-force application element 482 comprises a springy element 484.For some applications, at least a portion of springy element 484 iscurved at least partially about an inner surface of the wall of sleeve26, such as shown in FIGS. 9, 10, 12, 14, 15, and 16A-B. Typically,springy element 484 comprises an elastic material, such as a metal, suchas Nitinol or stainless steel.

For some applications (such as when elongated radial-force applicationelement 482 comprises springy element 484), as labeled in FIGS. 11A-D,elongated radial-force application element 482 is shaped so as to defineone or more axial base sections 510 (e.g., exactly two axial basesections 510A and 510B, as shown in FIGS. 11A-D), and one or more offsetsections 512 (e.g., exactly one offset section 512, as shown in FIG. 11A(and FIG. 10), or a plurality of offset sections 512 (e.g., between twoand 20, e.g., between two and ten, such as between two and six), asshown in FIGS. 11B-D). The one or more axial base sections 510 arecoaxial with a longitudinal axis 514 of elongated radial-forceapplication element 482, and the one or more offset sections 512 are notcoaxial with longitudinal axis 514. A greatest distance D between theone or more offset sections 512 and longitudinal axis 514 is typicallyat least 2 mm, no more than 10 mm (e.g., no more than 6 mm), and/orbetween 2 and 10 mm (e.g., between 2 and 6 mm), e.g., 4 mm.

For some applications, offset section(s) 512 are at least partiallystraight, such as shown in FIGS. 11A and 11B. For some applications,offset sections 512 are at least partially curved, such as shown inFIGS. 11C and 11D. For some applications, offset sections 512 are atleast partially serpentine, such as shown in FIG. 11D.

For some applications, the at least a portion of springy element 484 iscurved at least partially about the inner surface of the wall of sleeve26 in a single circumferential direction, such as shown in FIGS. 9, 10,14, 15, and 16A-B. Alternatively, for some applications, at least afirst portion 485A of springy element 484 is curved at least partiallyabout the inner surface of the wall of sleeve 26 in a firstcircumferential direction 486A, and at least a second portion 485B ofspringy element 484 is curved at least partially about the inner surfaceof the wall of sleeve 26 in a second circumferential direction 486Bcircumferentially opposite the first circumferential direction, such asshown in FIG. 12. This configuration may use any of the shapes shown inFIGS. 11A-D (with the shapes doubled), or other shapes. Thisconfiguration pushes against the wall of sleeve 26 and the tissue at atleast two circumferential locations around the sleeve, and may help holdthe rotational position of the sleeve, allow less accurate rotationalalignment, and/or help compensate for anatomical variability.

For some applications, such as shown in Section A-A of FIG. 9, elongatedradial-force application element 482 is configured to apply the forceagainst the wall of sleeve 26 around an angle α (alpha) that is lessthan 100% of a perimeter of the wall of sleeve 26 around a centrallongitudinal axis 516 of sleeve 26, such as around less than 75%, e.g.,less than 50%, such as less than 25%, of the perimeter of the wall ofsleeve 26. (Central longitudinal axis 516 runs along sleeve 26; thecross-section shown in Section A-A of FIG. 9 is perpendicular to thecentral longitudinal axis.) Force is not required to be applied around100% of the perimeter of the wall of sleeve 26 because a circumferentialportion of the wall faces the blood-filled volume of the chamber, ratherthan atrial tissue, and there would be no benefit to pushing the wall ofsleeve 26 against the blood-filled volume.

For some applications, such as shown in FIG. 13, elongated radial-forceapplication element 482 is helically symmetric; for these applications,springy element 484 typically comprises a coiled spring 490. For someapplications, when in a relaxed state, coiled spring 490 has an outerdiameter of at least 2.5 mm, no more than 10 mm, and/or between 2.5 and10 mm, such as at least 3.5 mm, no more than 6 mm, and/or between 3.5and 6 mm. For some applications, when in a relaxed state, the outerdiameter of coiled spring 490 is greater than (e.g., equals at least110% of, such as at least 130% of, e.g. at least 150% of) an innerdiameter of a second longitudinal portion 492 that is entirelylongitudinally distinct from first longitudinal portion 480 of sleeve26, when second longitudinal portion 492 is fully radially expanded.Coiled spring 490 is typically initially held constrained with a smallerdiameter in a separate tube smaller than the inner diameter of thedeployment sheath.

Reference is again made to FIGS. 9-16B. For some applications,longitudinal contracting member 30 of contracting assembly 40 isarranged only along at least a portion of second longitudinal portion492. For some of these applications, contracting assembly 40 isconfigured to contract the at least a portion of the second longitudinalportion 492.

Reference is made to FIG. 14. For some applications, first and secondlongitudinal portions 480 and 492 of sleeve 26 are configured such thatfirst longitudinal portion 480 either has, or is configured to assume, afirst average internal diameter D1 that is greater than a second averageinternal diameter D2 of second longitudinal portion 492. For example,first average internal diameter D1 may be at least 110% of D2, such asat least 150% of second average internal diameter D2. This largeraverage diameter enables elongated radial-force application element 482(e.g., springy element 484) to push a large surface area of sleeve 26against the atrial tissue, thereby better encouraging tissue growth,better inhibiting blood between the sleeve and the atrial tissue, andaccommodating variations in individual patient anatomy.

For some applications, first and second longitudinal portions 480 and492 collectively extend along an entire length of sleeve 26. Thisconfiguration, as well as the various options described below, may beused in combination with any of the configurations described herein withreference to FIGS. 9-13 and/or 15.

For some applications, first average internal diameter D1 of firstlongitudinal portion 480 of sleeve 26 is greater than second averageinternal diameter D2 of second longitudinal portion 492 of sleeve 26,when both first and second longitudinal portions 480 and 492 are fullyradially expanded (in these applications, typically both first andsecond longitudinal portions 480 and 492 are substantially radiallynon-extensible).

For some other applications, first longitudinal portion 480 of sleeve 26is radially elastic and thus able to stretch from an initial smalleraverage internal diameter to first average internal diameter D1, andsecond longitudinal portion 492 of sleeve 26 is substantially radiallynon-extensible, and thus cannot expand to a diameter beyond secondaverage internal diameter D2. For example, first longitudinal portion480 may comprise a first plurality of substantially non-extensiblefibers that extend longitudinally along the first longitudinal portion,and a second plurality of elastic fibers that are arrangedcircumferentially around the first longitudinal portion (typically,woven with the first plurality of fibers). Typically, first and secondlongitudinal portions 480 and 492 of sleeve 26 are substantiallylongitudinally non-extensible, i.e., a length thereof is substantiallyconstant, i.e., cannot be longitudinally stretched, under normal usageconditions. Optionally, first and second longitudinal portions 480 and492 of sleeve 26 have a same diameter (equal to second average internaldiameter D2) when first longitudinal portion 480 is not elasticallystretched. Alternatively, for some applications, first and secondlongitudinal portions 480 and 492 of sleeve 26 are woven, and firstlongitudinal portion 480 of sleeve 26 is more loosely woven than secondlongitudinal portion 492 of sleeve 26. Further alternatively, for someapplications, first longitudinal portion 480 of sleeve 26 is radiallystretchable, and second longitudinal portion 492 of sleeve 26 issubstantially radially non-extensible. For example, first longitudinalportion 480 may comprise a first plurality of substantiallynon-extensible fibers that extend longitudinally along the firstlongitudinal portion, and a second plurality of stretchable fibers thatare arranged circumferentially around the first longitudinal portion(typically, woven with the first plurality of fibers).

For some applications, such as shown in FIGS. 9-10 and 12-15, sleeve 26has (a) a first sleeve end 51 (which may correspond to distal end 51 ofsleeve 26, as shown, or to the proximal end, configuration not shown),and (b) a second sleeve end 49 (which may correspond to proximal end 49of sleeve 26, as shown, or to the distal end, configuration not shown).For some applications, elongated radial-force application element 482has (a) a first radial-force-application-element longitudinal end 496that is between 2 and 6 cm from first sleeve end 51, measured whensleeve 26 is fully longitudinally extended, and (b) a secondradial-force-application-element longitudinal end 498 that is within 1.5cm of first sleeve end 51, measured when sleeve 26 is fullylongitudinally extended.

For some applications, such as shown in FIGS. 9-10 and 12-15,implantable structure 22 (e.g., the annuloplasty ring) further comprises(a) a first coupling element 456, which is coupled to the annuloplastyring within 1.5 cm of first sleeve end 51, measured when sleeve 26 isfully longitudinally extended, and (b) second coupling element 260, asdescribed above with reference to FIGS. 6 and 7A-B. Second couplingelement 260 is configured to be coupleable to first coupling element456, and is fixed to implantable structure 22 (e.g., the annuloplastyring) within 1.5 cm of second sleeve end 49, measured when sleeve 26 isfully longitudinally extended. For some applications, at least one offirst and second coupling elements 456 and 260 comprises a hook.Alternatively or additionally, for some applications, at least one ofthe first and second coupling elements comprises a loop. For example, inthe configurations shown in FIGS. 9-15, first coupling element 456comprises a hook, and second coupling element 260 comprises a loop.Alternatively, for example, both the first and the second couplingelements comprises loops, such as shown in FIGS. 8B and 8D, and thecoupling elements are coupled together such as by placing one of anchors38 through both loops and into cardiac tissue.

Elongated radial-force application element 482 is typically fixed tosleeve 26 at least near first radial-force-application-elementlongitudinal end 496, such that elongated radial-force applicationelement 482 is arranged as a cantilever. Typically, elongatedradial-force application element 482 is fixed to sleeve 26 at least nearfirst radial-force-application-element longitudinal end 496, such thatfirst radial-force-application-element longitudinal end 496 isrotationally fixed with respect to the sleeve, in order to allowtwisting of elongated radial-force application element 482 to storespring energy in elongated radial-force application element 482 nearfirst radial-force-application-element longitudinal end 496. The shapeof first radial-force-application-element longitudinal end 496 may aidin rotationally fixing the end with respect to the sleeve. For example,first radial-force-application-element longitudinal end 496 may includea circumferentially-oriented component, as shown in the figures.

A portion of elongated radial-force application element 482 may bethreaded through the fabric of the sleeve, and/or sewn (e.g., sutured)to the fabric of the sleeve to hold the elongated radial-forceapplication element in place during deployment, and/or the elongatedradial-force application element may be held in place after implantationby one or more of anchors 38, such as two or more anchors 38F.

For some applications, such as shown in FIGS. 9-15, contractingmechanism 28 (e.g., housing 44 thereof) is fixed along sleeve 26 within30 mm, such as within 15 mm, of second sleeve end 49 (i.e., the same endof the sleeve near which second coupling element 260 is coupled),measured when sleeve 26 is fully longitudinally extended. For example,contracting mechanism 28 (e.g., housing 44 thereof) may be fixed atsecond sleeve end 49. Alternatively, for some applications, contractingmechanism 28 (e.g., housing 44 thereof) is fixed at least 5 mm fromsecond sleeve end 49, e.g., between 5 and 30 mm, such as between 5 and15 mm, from second sleeve end 49. Second coupling element 260 may becoupled to contracting mechanism 28 (e.g., to housing 44).Alternatively, second coupling element 260 may be otherwise coupled tosleeve 26 (such as directly coupled), in which case contractingmechanism 28, e.g., housing 44 thereof, may be coupled to sleeve 26 at agreater longitudinal distance from the end of the sleeve, and one ormore of anchors 38 may be coupled to the sleeve longitudinally betweenthe contracting mechanism and the sleeve end, such as describedhereinabove with reference to FIGS. 1, 2A-I, 3, and 4.

For some applications, such as shown in FIGS. 9-14, implantablestructure 22 (e.g., the annuloplasty ring) further comprises asubstantially longitudinally non-extensible linking member 450, i.e., alength thereof is substantially constant, i.e., cannot be longitudinallystretched, under normal usage conditions. Linking member 450 typicallyhelps prevent long-term dilation of the anterior annulus. Linking member450 is typically configured not to apply any force to the wall of firstlongitudinal portion 480 of sleeve 26. Typically, linking member 450 isnot configured as a spring. For some applications, linking member 450comprises a metal (e.g., Nitinol or stainless steel) or a polymer. Forsome applications, linking member 450 is rigid, while for otherapplications, the linking member is not rigid.

Linking member 450 has first and second linking-member ends 452 and 454.Linking member 450 is at least partially disposed within and covered byfirst longitudinal portion 480 of sleeve 26. Typically, at least 30%,such as at least 75% or at least 90% of a length of linking member 450is disposed within and covered by first longitudinal portion 480 ofsleeve 26. Over time after implantation, linking member 450 becomesfixed to anterior portion 116 of the annulus. Second linking-member end454 comprises (e.g., is shaped so as to define, or is fixed to) firstcoupling element 456. Second linking-member end 454 either protrudesfrom first sleeve end 51, or is recessed within first sleeve end 51. Alongitudinal portion of linking member 450 in a vicinity of firstlinking-member end 452 is typically coupled to sleeve 26. For example,the portion may be threaded through the fabric of the sleeve, and/orsewn (e.g., sutured) to the fabric of the sleeve to hold the linkingmember in place during deployment. Optionally, a longitudinal portion oflinking member 450 in a vicinity of first linking-member end 452 is heldin place after implantation by one or more of anchors 38, such as two ormore anchors 38F (configuration not shown). Optionally, the linkingmember is not initially coupled to the sleeve, but is instead held inplace by a delivery tool during the implantation procedure, until beingcoupled to the sleeve during the implantation procedure. Typically,linking member 250 has a length of at least 2 cm, no more than 6 cm,and/or between 2 and 6 cm.

For some applications, at least first longitudinal portion 480 of sleeve26 is substantially longitudinally non-extensible, i.e., a lengththereof is substantially constant, i.e., cannot be longitudinallystretched, under normal usage conditions. In these applications, firstlongitudinal portion 480 typically helps prevent long-term dilation ofthe anterior annulus.

For some applications, such as shown in FIG. 15, first coupling element456 is fixed to the wall of sleeve 26 within 1.5 cm of first sleeve end51, measured when sleeve 26 is fully longitudinally extended.Implantable structure 22 typically does not comprise linking member 450in these applications. In these applications, at least firstlongitudinal portion 480 of sleeve 26 is substantially longitudinallynon-extensible, and first longitudinal portion 480 typically helpsprevent long-term dilation of the anterior annulus.

Reference is made to FIGS. 9-15. Typically, sleeve 26 is placed entirelyaround an annulus of the atrioventricular valve, e.g., the mitral valve.For applications in which sleeve 26 has first and second sleeve ends 51and 49, as described hereinabove with reference to FIGS. 9-14, sleeve 26is introduced into the left atrium while first and second sleeve ends 51and 49 are not coupled to each other, and thereafter, in the leftatrium, sleeve 26 is arranged entirely around the annulus to form theclosed loop.

Reference is still made to FIGS. 9-16. For some applications, duringplacement, after fastening sleeve 26 to the portion of the annulus, thehealthcare professional twists elongated radial-force applicationelement 482 (and optionally first longitudinal portion 480 of sleeve26), and then, typically, links first and second coupling elements 456and 260. Optionally, such twisting may serve one or both of thefollowing purposes: (1) the twisting may store energy in springy element484 for exertion of torque against the wall of the sleeve, and (2) thetwisting may rotationally align springy element 484 in the desiredradial direction. Alternatively or additionally to twisting for thefirst of these purposes, springy element 484 may be pre-loaded (twisted)to store energy before implantation in the subject, such as immediatelybefore implantation or during manufacture.

Reference is again made to FIGS. 8A-D. The techniques described withreference to these figures regarding coupling element 256 may beimplemented for coupling element 456 of the configuration described withreference to FIGS. 9-15.

Reference is made to FIGS. 16A-B, which are schematic illustrations ofimplantable structure 22 in which sleeve 26 is shaped so as to define anintegrally closed loop having no sleeve ends, in accordance withrespective applications of the present invention. In these applications,the wall of sleeve 26 typically is shaped so as to define a lateralopening 500 through which anchor deployment manipulator 24 isintroduced. For some applications, elongated radial-force applicationelement 482 has (a) a first radial-force-application-elementlongitudinal end 496 that is at least 2 cm, no more than 6 cm, and/orbetween 2 and 6 cm from housing 44 of contracting assembly 40 (housing44 is fixed to sleeve 26), measured when sleeve 26 is fullylongitudinally extended, and (b) a secondradial-force-application-element longitudinal end 498 that is within 1.5cm of housing 44, measured when sleeve 26 is fully longitudinallyextended. Alternatively, for some applications, firstradial-force-application-element longitudinal end 496 is within 1.5 cmof housing 44, measured when sleeve 26 is fully longitudinally extended,and second radial-force-application-element longitudinal end 498 is atleast 2 cm, no more than 6 cm, and/or between 2 and 6 cm from housing 44of contracting assembly 40, measured when sleeve 26 is fullylongitudinally extended.

For some applications, such as shown in FIG. 16B, first and secondlongitudinal portions 480 and 492 of sleeve 26 are configured such thatfirst longitudinal portion 480 either has, or is configured to assume, afirst average internal diameter D1 that is greater than a second averageinternal diameter D2 of second longitudinal portion 492. For example,first average internal diameter D1 may be at least 110% of secondaverage internal diameter D2, such as at least 150% of second averageinternal diameter D2. First average internal diameter D1 may be achievedusing the techniques described hereinabove with reference to FIG. 14.For other applications, such as shown in FIG. 16A, the entire sleeve(i.e., first and second longitudinal portions 480 and 492) has aconstant internal diameter.

For some applications, as shown in FIGS. 16A-B, implantable structure 22is implanted with contracting mechanism 28 disposed near left fibroustrigone 142, while for other applications (not shown, but similar to thearrangement shown in FIG. 7B), implantable structure 22 is implantedwith contracting mechanism 28 disposed near right fibrous trigone 144.

Reference is now made to FIG. 17, which is a schematic illustration ofanother configuration of implantable structure 22 implanted around themitral valve, in accordance with an application of the presentinvention. In this configuration, elongated radial-force applicationelement 482 comprises an inflatable element 494, such as a balloon.After fastening sleeve 26 to the portion of the annulus (and,optionally, after linking first and second coupling elements 456 and260), the healthcare professional inflates inflatable element 494,typically with a liquid (such as saline solution) or a gel. For someapplications, inflatable element 494 is provided separately fromimplantable structure 22, and the healthcare professional introducesinflatable element 494, while uninflated, into sleeve 26, typicallyafter fastening sleeve 26 to the portion of the annulus (and,optionally, after linking first and second coupling elements 456 and260), and then inflates inflatable element 494. These inflationtechniques may be used with any of the techniques described herein withreference to FIGS. 9-16B, mutatis mutandis.

For some applications, as shown in FIG. 17, implantable structure 22 isimplanted with contracting mechanism 28 disposed near left fibroustrigone 142, while for other applications (not shown, but similar to thearrangement shown in FIG. 7B), implantable structure 22 is implantedwith contracting mechanism 28 disposed near right fibrous trigone 144.This latter arrangement may facilitate placement of the first-deployed,distal-most anchor 38 near right fibrous trigone 144, which is above thefossa ovalis, and the linking of first and second coupling elements 456and 260 later in the implantation procedure, for applications in whichthese coupling elements are provided, such as described hereinbelow.

Reference is now made to FIGS. 18A and 18B. FIG. 18A is a schematicillustration of another configuration of implantable structure 22, priorto implantation, in accordance with an application of the presentinvention, and FIG. 18B is a schematic illustration of implantablestructure 22 in the configuration of FIG. 18A after implantationentirely around the annulus of mitral valve 130, before a longitudinalportion of sleeve 26 has been contracted, in accordance with anapplication of the present invention. In this configuration, flexiblesleeve 26 is placed entirely around an annulus of mitral valve 130 in aclosed loop. For some applications, sleeve 26 is introduced into leftatrium 124 while first and second sleeve ends are not coupled to eachother. Thereafter, in the left atrium, the sleeve is arranged entirelyaround the annulus to form the closed loop.

Sleeve 26 is fastened to the annulus by coupling a plurality of tissueanchors 38 to the annulus. Tissue anchors 38 are coupled with:

-   -   a first non-zero longitudinal density along a posterior portion        of the annulus between left and right fibrous trigones 142 and        144 of the annulus, including the trigones, which density is        equal to (a) a number of tissue anchors 38 coupled to the        annulus along the posterior portion of the annulus divided        by (b) a length of the posterior portion of the annulus        (measured along the annulus),    -   and a second non-zero longitudinal density along an anterior        portion of the annulus between left and right fibrous trigones        142 and 144 of the annulus, not including the trigones, which        density is equal to (a) a number of tissue anchors 38 coupled to        the annulus along the anterior portion of the annulus divided        by (b) a length of the anterior portion of the annulus (measured        along the annulus).

The first longitudinal density is greater than the second longitudinaldensity. For some applications, the first longitudinal density is atleast twice the second longitudinal density, such as at least 2.5 thesecond longitudinal density, e.g., at least 3 times the secondlongitudinal density. For example, tissue anchors 38A (and, optionally38C) may be fastened along the posterior portion of the annulus, andtissue anchors 38B may be fastened along the anterior portion of theannulus. After the tissue anchors are fastened to the annulus, alongitudinal portion of the sleeve is contracted, such as by causing thelongitudinal contracting member to apply a force to the longitudinalportion of the sleeve, such as by actuating contracting assembly 40.

Alternatively or additionally, for some applications, sleeve 26comprises a plurality of radiopaque markers 39, which are positionedalong the sleeve at respective longitudinal sites, such as describedhereinabove with reference to FIG. 1. The markers may provide anindication in a radiographic image (such as a fluoroscopy image) of howmuch of the sleeve has been deployed at any given point during animplantation procedure, in order to enable setting a desired distancebetween anchors 38 along the sleeve, and thus the desired differinglongitudinal densities of the anchors.

For some applications, as shown in FIG. 18B, implantable structure 22 isimplanted with contracting mechanism 28 disposed near left fibroustrigone 142, while for other applications (not shown, but similar to thearrangement shown in FIG. 7B), implantable structure 22 is implantedwith contracting mechanism 28 disposed near right fibrous trigone 144.

Reference is now made to FIG. 19, which is a schematic illustration ofimplantable structure 22 after implantation around the annulus of mitralvalve 130, in accordance with an application of the present invention.In this configuration, flexible sleeve 26 is placed at least partiallyaround an annulus of mitral valve 130, such as partially around theannulus, as shown in FIG. 19, or entirely around the annulus in a closedloop, such as shown in FIG. 4, 5, 7A-B, 10, 16A-B, 17, or 18B,optionally using any of the techniques described herein with referenceto these figures. For some applications in which the sleeve is placedentirely around the annulus, sleeve 26 is introduced into left atrium124 while first and second sleeve ends are not coupled to each other;thereafter, in the left atrium, sleeve 26 is arranged entirely aroundthe annulus to form the closed loop. FIG. 19 shows the annulus before alongitudinal portion of sleeve 26 has been contracted, as describedbelow.

Sleeve 26 is fastened to the annulus by coupling a plurality of tissueanchors 38 to the annulus, including first, second, and third tissueanchors 38G, 38H, and 38I, as follows:

-   -   one or more first tissue anchors 38G are coupled to the annulus        along a lateral scallop (P1) of the posterior leaflet, with a        first longitudinal density, which density is equal to (a) a        number of first tissue anchors 38G coupled to the annulus along        the lateral scallop (P1) divided by (b) a length of the lateral        scallop (P1) along the annulus,    -   a plurality of second tissue anchors 38H (e.g., at least 3        tissue anchors, such as at least five tissue anchors) are        coupled to the annulus along a middle scallop (P2) of the        posterior leaflet, with a second longitudinal density, which        density is equal to (a) a number of second tissue anchors 38H        coupled to the annulus along the middle scallop (P2) divided        by (b) a length of the middle scallop (P2) along the annulus,        and    -   one or more third tissue anchors 38I are coupled to the annulus        along a medial scallop (P3) of the posterior leaflet, with a        third longitudinal density, which density is equal to (a) a        number of third tissue anchors 38I coupled to the annulus along        the medial scallop (P3) divided by (b) a length of the medial        scallop (P3) along the annulus.

Tissue anchors 38 may optionally comprise additional tissue anchorsother than tissue anchors 38G, 38H, and 38I, not coupled along theposterior leaflet. After the tissue anchors are fastened to the annulus,a longitudinal portion of sleeve 26 is contracted, such as by causingthe longitudinal contracting member to apply a force to the longitudinalportion of the sleeve, such as by actuating contracting assembly 40.

The longitudinal densities are characterized by at least one of thefollowing: (a) the second longitudinal density is at least twice thefirst longitudinal density (such as at least 2.5 the first longitudinaldensity, e.g., at least 3 times the first longitudinal density), and (b)the second longitudinal density is at least twice the third longitudinaldensity (such as at least 2.5 the third longitudinal density, e.g., atleast 3 times the third longitudinal density). For some applications,both (a) the second longitudinal density is at least twice the firstlongitudinal density (such as at least 2.5 the first longitudinaldensity, e.g., at least 3 times the first longitudinal density), and (b)the second longitudinal density is at least twice the third longitudinaldensity (such as at least 2.5 the third longitudinal density, e.g., atleast 3 times the third longitudinal density).

For some applications, as shown in FIG. 19, implantable structure 22 isimplanted with contracting mechanism 28 disposed near left fibroustrigone 142, while for other applications (not shown, but similar to thearrangement shown in FIG. 7B), implantable structure 22 is implantedwith contracting mechanism 28 disposed near right fibrous trigone 144.

Reference is now made to FIG. 20, which is a schematic illustration ofimplantable structure 22 after implantation around the annulus of mitralvalve 130, in accordance with an application of the present invention.FIG. 20 shows implantable structure 22 after a longitudinal portion ofsleeve 26 has been contracted, such as by actuating contracting assembly40. The techniques described with reference to FIG. 20 may optionally beused in combination with the techniques described above with referenceto FIG. 19.

Tissue anchors 38, including second tissue anchors 38H, compriserespective anchor heads 320 and tissue coupling elements 322. Typically,anchor heads 320 are circular; alternatively, they have another shape,such as of an ellipse or a polygon (e.g., a hexagon or a square). Theplurality of tissue anchors 38 are coupled to the annulus such that,after the longitudinal portion of sleeve 26 has been contracted (such asby actuating contracting assembly 40 to contract the longitudinalportion), each of anchor heads 320 of at least two of second tissueanchors 38H coupled along the middle scallop (P2) touches at least onelongitudinally-adjacent anchor head 320; for example, each of anchorheads 320 of at least three of tissue anchors 38H touches at least onelongitudinally-adjacent anchor head 320.

Typically, before the longitudinal portion of sleeve 26 has beencontracted, anchor heads 320 of the at least two of second tissueanchors 38H do not touch any longitudinally-adjacent anchor heads 320.Before the longitudinal portion of sleeve 26 has been contracted, theanchors are coupled to the sleeve and tissue at distances between theanchors that are less than the planned distances that the anchors movetoward each other during contraction of the longitudinal portion ofsleeve 26. As a result, the anchor heads touch each other upon suchcontraction.

By way of example, FIG. 20 shows three of tissue anchors 38H touching atleast one longitudinally-adjacent anchor head 320. Each of thelongitudinally-outer touching anchor heads touches onelongitudinally-adjacent anchor head (the middle longitudinally-touchinganchor head), and the middle longitudinally-touching anchor head touchestwo longitudinally-adjacent anchor heads (the outer touching anchorheads).

This touching of longitudinally-adjacent anchor heads 320 inhibitslongitudinal contraction of sleeve 26 in the longitudinal area of theseanchors, so as to facilitate reshaping of the annulus in a desiredmanner. These longitudinally-adjacent anchor heads 320 thus aredual-function, and serve to both anchor their respective anchors to thesleeve and to inhibit contraction of the sleeve.

For some applications, as shown in FIG. 20, the plurality of tissueanchors 38 is coupled to the annulus such that, after the longitudinalportion of sleeve 26 has been contracted, such as by causing thelongitudinal contracting member to apply a force to the longitudinalportion of the sleeve, such as by actuating contracting assembly 40:

-   -   none of anchor heads 320 of first tissue anchors 38G coupled        along the lateral scallop (P1) touches any of the other anchor        heads of tissue anchors 38; and/or    -   none of anchor heads 320 of third tissue anchors 38I coupled        along the medial scallop (P3) touches any of the other anchor        heads of tissue anchors 38.

For some applications, the plurality of tissue anchors 38 are coupled tothe annulus such that, after the longitudinal portion of sleeve 26 hasbeen contracted, such as by causing the longitudinal contracting memberto apply a force to the longitudinal portion of the sleeve, such as byactuating contracting assembly 40:

-   -   a first number of anchor heads 320 of first tissue anchors 38G        coupled along the lateral scallop (P1) touch at least one        longitudinally-adjacent anchor head, and (b) a second number of        anchor heads 320 of the tissue anchors coupled along the middle        scallop (P2) touch at least one longitudinally-adjacent anchor        head, the second number greater than the first number; and/or    -   a second number of anchor heads 320 of second tissue anchors 38H        coupled along the middle scallop (P2) touch at least one        longitudinally-adjacent anchor head, and (b) a third number of        anchor heads 320 of third tissue anchors 38I coupled along the        medial scallop (P3) touch at least one longitudinally-adjacent        anchor head, the second number greater than the third number.

For some applications, as shown in FIG. 20, implantable structure 22 isimplanted with contracting mechanism 28 disposed near left fibroustrigone 142, while for other applications (not shown, but similar to thearrangement shown in FIG. 7B), implantable structure 22 is implantedwith contracting mechanism 28 disposed near right fibrous trigone 144.

Reference is now made to FIG. 21, which is a schematic illustration ofimplantable structure 22 after implantation around the annulus of mitralvalve 130, in accordance with an application of the present invention.FIG. 21 shows the annulus before a longitudinal portion of sleeve 26 hasbeen contracted, as described below. The techniques described withreference to FIG. 21 may optionally be used in combination with thetechniques described hereinabove with reference to FIG. 19, and/or thetechniques described hereinabove with reference to FIG. 20.

In this configuration, flexible sleeve 26 is placed at least partiallyaround an annulus of mitral valve 130, such as partially around theannulus, as shown in FIG. 21, or entirely around the annulus in a closedloop, such as shown in FIG. 4, 5, 7A-B, 10, 16A-B, 17, or 18B,optionally using any of the techniques described with reference to thesefigures. For some applications in which the sleeve is placed entirelyaround the annulus, sleeve 26 is introduced into left atrium 124 whilefirst and second sleeve ends are not coupled to each other; thereafter,in the left atrium, sleeve 26 is arranged entirely around the annulus toform the closed loop.

Sleeve 26 is fastened to the annulus by coupling a plurality of tissueanchors 38 to the annulus, including tissue anchors 38J and 38K, suchthat:

-   -   a first set 324 of exactly three of tissue anchors 38J is        disposed in succession along a first portion of longitudinal        contracting member 30 with a first distance D9 between        longitudinal-end tissue anchors of first set 324, measured along        the annulus, and    -   a second set 328 of exactly three of tissue anchors 38K is        disposed in succession along a second portion of longitudinal        contracting member 30 with a second distance D10 between        longitudinal-end tissue anchors of second set 328, measured        along the annulus,

First distance D9 equals at least twice second distance D10, such as atleast 2.5 times second distance D10, e.g., at least 3 times seconddistance D10. First distance D9 is measured between closest portions ofthe longitudinal-end tissue anchors of first set 324, and seconddistance D10 is measured between closest portions of thelongitudinal-end tissue anchors of second set 328. First and second sets324 and 328 do not share any common tissue anchors 38. Typically, theplurality of tissue anchors 38 comprises additional tissue anchors otherthan tissue anchors 38J and 38K. After the tissue anchors are fastenedto the annulus, a longitudinal portion of sleeve 26 is contracted bycausing the longitudinal contracting member to apply a force to thelongitudinal portion of the sleeve, such as by actuating contractingassembly 40. Providing the greater number of anchoring points withsecond set 328 better distributes forces among the anchors of this set.

For some applications, as shown in FIG. 21, implantable structure 22 isimplanted with contracting mechanism 28 disposed near left fibroustrigone 142, while for other applications (not shown, but similar to thearrangement shown in FIG. 7B), implantable structure 22 is implantedwith contracting mechanism 28 disposed near right fibrous trigone 144.

Reference is now made to FIGS. 22A-D, which are schematic illustrationsof another configuration of system 20 for repairing a dilatedatrioventricular valve, and a method for deploying the system, inaccordance with an application of the present invention. Thisconfiguration may be used in combination with any of the techniques andconfigurations described herein with reference to FIGS. 1, 2A-I, 3, 19,20, 21, 24, 25A-B, and/or 26.

In this configuration, system 20 further comprises a linking bridgeelement 200, which is configured to be coupled to sleeve 26 in order tolink first and second sleeve ends 51 and 49 of sleeve 26 of implantablestructure 22 via linking bridge element 200. To this end, linking bridgeelement 200 typically comprises first and second bridge couplinginterfaces 210A and 210B, which are configured to be coupled tocorresponding first and second sleeve coupling interfaces 212A and 212Bof sleeve 26, which are disposed within 1.5 cm of first and secondsleeve ends 51 and 49, respectively, measured when the sleeve is fullylongitudinally extended, such as at first and second sleeve ends 51 and49, respectively. For example, first and second bridge couplinginterfaces 210A and 210B may comprise female interfaces (as shown), andfirst and second sleeve coupling interfaces 212A and 212B may comprisemale interfaces (as shown), which are configured to snap into the femaleinterfaces. Alternatively, first and second sleeve coupling interfaces212A and 212B may comprise female interfaces, such as rings (e.g.,comprising a metal or a plastic) integrated into the wall of sleeve 26(configurations not shown), and first and second bridge couplinginterfaces 210A and 210B may comprise male interfaces (configuration notshown), which are configured to snap into the female interfaces. Furtheralternatively, the interfaces comprise other coupling structures, as isknown in the art, such as coupling structures that snap together.

Typically, linking bridge element 200 has a length of at least 1 cm, nomore than 5 cm, and/or between 1 and 5 cm, such as at least 1.5 cm, nomore than 3.5 cm, and/or between 1.5 and 3.5 cm, e.g., 2 cm. Typically,first and second bridge coupling interfaces 210A and 210B are disposedwithin 1 cm (such as within 0.5 cm) of first and second ends 216A and216B of linking bridge element 200, respectively, e.g., between 0.5 cmand 1 cm of first and second ends 216A and 216B of linking bridgeelement 200, respectively. For some applications, linking bridge element200 comprises a metal or a polymer that provides longitudinal stabilitywhile maintaining some flexibility in other directions. Optionally,linking bridge element 200 further comprises a fabric or other coatingfor tissue growth enhancement. For some applications, linking bridgeelement 200 comprises elongated radial-force application element 482,such as described hereinabove with reference to FIGS. 9-15 and/or 17.

For some applications, system 20 comprises first and second flexiblelongitudinal guide members 214A and 214B, which are removably coupled tosleeve 26 within 1.5 cm of first and second sleeve ends 51 and 49 (e.g.,with 0.5 cm of the sleeve ends, or at the sleeve ends), respectively,measured when the sleeve is fully longitudinally extended. First andsecond flexible longitudinal guide members 214A and 214B extend fromfirst and second sleeve ends 51 and 49, respectively, away from sleeve26. First and second flexible longitudinal guide members 214A and 214Bmay be directly or indirectly coupled to sleeve 26. For configurationsin which first and second flexible longitudinal guide members 214A and214B are indirectly coupled to sleeve 26, the longitudinal guide membersmay be coupled to respective intermediary elements at locations beyondthe end of the sleeve (but still within 1.5 cm of the respective sleeveends). For example, first and second flexible longitudinal guide members214A and 214B may be (a) removably coupled to first and second sleevecoupling interfaces 212A and 212B, respectively (in which case thelongitudinal guide members may be indirectly coupled to the sleeve),and/or (b) the wall of sleeve 26 (in which case the longitudinal guidemembers are directly coupled to the sleeve). For example, first andsecond flexible longitudinal guide members 214A and 214B may compriserespective sutures, wires, or strings.

The longitudinal guide members are configured to guide first and secondbridge coupling interfaces 210A and 210B to corresponding locations onsleeve 26, such as first and second sleeve coupling interfaces 212A and212B, during an implantation procedure, as shown in FIGS. 22A-C. Thelongitudinal guide members removably pass through respective openingsdefined by linking bridge element 200, and then through a delivery tube220 in which linking bridge element 200 is disposed for delivery to theatrium. For some applications, the respective openings are defined byfirst and second bridge coupling interfaces 210A and 210B, respectively(as shown). For other applications, the respective openings are locatedelsewhere on linking bridge element 200, typically within 10 mm, such aswithin 5 mm, of first and second bridge coupling interfaces 210A and210B, respectively. (Optionally, longitudinal member 86, describedhereinabove with reference to FIG. 21, also passes through delivery tube220.)

For some applications, each of the longitudinal guide members is doubledover and threaded through its respective sleeve coupling interfaceand/or sleeve end. After the linking bridge element has been coupled tosleeve 26 of implantable structure 22, the longitudinal guide membersare removed by pulling on one end of each of the longitudinal guidemembers, typically from outside of the patient's body. Alternatively,each of the longitudinal guide members is decoupled from the sleeve insome other manner, such as using techniques described in theabove-mentioned '604 application for decoupling longitudinal member 86from contracting mechanism 40.

Typically, as described hereinabove, implantable structure 22 compriseslongitudinal contracting member 30, which is configured tolongitudinally contract a longitudinal portion of sleeve 26, asdescribed hereinabove. Longitudinal contracting member 30 may bedisposed with respect to the sleeve in any of the arrangements describedhereinabove, including those regarding the extent to which thecontracting member extends along the length of sleeve. First and secondflexible longitudinal guide members 214A and 214B are separate anddistinct from longitudinal contracting member 30; in other words, firstand second flexible longitudinal guide members 214A and 214B are notfixed to longitudinal contracting member 30, and are not parts of acommon longitudinal member.

Typically, when first and second flexible longitudinal guide members214A and 214B are removably coupled to sleeve 26 of implantablestructure 22:

-   -   no portion of either first flexible longitudinal guide member        214A or second flexible longitudinal guide member 214B is        disposed more than 1.5 cm from first and second sleeve ends 51        and 49, respectively, measured when the sleeve is fully        longitudinally extended;    -   first and second flexible longitudinal guide members 214A and        214B are collectively disposed along less than 30% of a length        of sleeve 26, such as less than 5% of the length of the sleeve,        measured when the sleeve is fully longitudinally extended;        and/or    -   for applications in which implantable structure 22 comprises        longitudinal contracting member 30, first and second flexible        longitudinal guide members 214A and 214B do not longitudinally        overlap longitudinal contracting member 30 (i.e., are not        disposed at any common longitudinal locations with longitudinal        contracting member 30).

Alternatively, for some applications, system 20 comprises a singleflexible longitudinal guide member 214 which removably passes throughthe entire sleeve 26 (configuration not shown). After the linking bridgeelement has been coupled to sleeve 26 of implantable structure 22, thelongitudinal guide member is removed by pulling on one end of thelongitudinal guide member, typically from outside of the patient's body.Alternatively, the longitudinal guide member is decoupled from thesleeve in some other manner, such as using techniques described in theabove-mentioned '604 application for decoupling longitudinal member 86from contracting mechanism 40.

After first and second bridge coupling interfaces 210A and 210B havebeen guided over first and second flexible longitudinal guide members214A and 214B to corresponding first and second sleeve couplinginterfaces 212A and 212B, as shown in FIGS. 22A-C, first and secondbridge coupling interfaces 210A and 210B are coupled to correspondingfirst and second sleeve coupling interfaces 212A and 212B, also as shownin FIG. 24C. For example, first and second tubes 222A and 222B may beintroduced through delivery tube 220 and over first and second flexiblelongitudinal guide members 214A and 214B, respectively, and used to pushthe corresponding coupling interfaces against each other, until theysnap together, as shown in FIG. 22C.

FIG. 22D shows linking bridge element 200 coupled to sleeve 26 ofimplantable structure 22, after the delivery tool has been removed fromthe atrium.

For applications in which implantable structure 22 compriseslongitudinal contracting member 30, the implantation method typicallycomprises:

-   -   during a percutaneous transcatheter procedure, placing sleeve 26        of implantable structure 22 partially around an annulus of a        valve of a subject, such as a mitral valve or tricuspid valve        (typically around all or a portion of a posterior portion of the        annulus between fibrous trigones of the valve);    -   anchoring sleeve 26 to cardiac tissue, such as described        hereinabove with reference to FIGS. 2G-I;    -   coupling linking bridge element 200 to sleeve 26, as described        hereinabove, typically along all or a portion of an anterior        portion of the annulus between the fibrous trigones; and    -   thereafter, contracting a longitudinal portion of sleeve 26 by        causing longitudinal contracting member 30 to apply a        contracting force to the longitudinal portion of the sleeve, as        described hereinabove.

Thus, the contracting of the sleeve is not performed simultaneously withthe coupling of the linking bridge element to the sleeve. Moreover,longitudinal contracting member 30 does not serve as either of first andsecond flexible longitudinal guide members 214A and 214B.

Optionally, for some applications, system 20 comprises one or morebridge anchors 224 (e.g., one, two, or three bridge anchors 224), whichare used to couple linking bridge element 200 to tissue at the anteriorportion of the annulus. For some applications, the one or more bridgeanchors 224 are deployed using anchor deployment manipulator 24,described hereinabove.

Reference is now made to FIGS. 23A-B, which are schematic illustrationsof another configuration of linking bridge element 200, in accordancewith an application of the present invention. Other than as describedbelow, this configuration is identical to the configuration describedhereinabove with reference to FIGS. 22A-D.

In this configuration, first and second bridge coupling interfaces 210Aand 210B are male interfaces, which are configured to pierce the wall ofsleeve 26, thereby becoming coupled to the sleeve. For example, thecoupling elements may be shaped as harpoons or other barbed structures.In this configuration, sleeve 26 typically does not comprise anycoupling interfaces or coupling elements.

Reference is now made to FIG. 24, which is a schematic illustration ofcontracting mechanism 28, disassembled to show a relationship amongindividual components of the contracting mechanism, in accordance withan application of the present invention. The components are arranged andfunction as described with reference to FIG. 7 of the above-mentioned'604 publication, mutatis mutandis.

Reference is made to FIGS. 25A-B and 26, which are schematicillustrations of a valve prosthesis assembly 400, in accordance withrespective applications of the present invention. Valve prosthesisassembly 400 comprises a prosthetic heart valve 410 that is couplable toa base ring 422. Prosthetic heart valve 410 is used to replace a nativediseased heart valve. Valve 410 comprises a plurality of artificialleaflets 430, which comprise a pliant material. Valve 410 may implementtechniques known in the artificial valve art, such as described, forexample, in US Patent Application Publication 2007/0255400 toParravicini et al., US Patent Application Publication 2004/0122514 toFogarty et al., US Patent Application Publication 2007/0162111 toFukamachi et al., and/or US Patent Application Publication 2008/0004697to Lichtenstein et al., all of which are incorporated herein byreference.

Valve 410 further comprises an annular base 432, to which artificialleaflets 430 are coupled. Annular base 432 is configured to be couplableto base ring 422 during an implantation procedure. For example, as shownin FIG. 26, base ring 422 may comprise one or more coupling elements434, such as clips or magnets, which are configured to be coupled tocorresponding coupling elements on a lower surface of annular base 432(not visible in the figures). Alternatively or additionally, annularbase 432 may be configured to be placed within the opening defined bybase ring 422, as shown in FIG. 25A. To hold the annular base coupled tothe base ring, the base ring is tightened around the annular base, asshown in FIG. 25B, typically using one or more of the techniquesdescribed hereinabove for contracting implantable structures. Typically,valve prosthesis assembly 400, such as annular base 432 thereof, isconfigured to push and hold open the intact diseased native leaflets.

Base ring 422 implements one or more of the techniques of implantablestructure 22 described hereinabove. In particular, base ring 422 may becoupled to the annulus of the native diseased valve using the anchoringtechniques described hereinabove. In addition, base ring 422 typicallycomprises sleeve 26 and contracting mechanism 28, which may, for someapplications, comprise a rotatable structure, such as a spool 46, whichis typically implemented using techniques described herein. Thecontracting mechanism is arranged to contract base ring 422, e.g., therotatable structure is arranged such that rotation thereof contractsbase ring 422, typically using techniques described herein. Suchtightening may serve to couple base ring 422 to annular base 432, asshown in FIG. 25B. Alternatively or additionally, such tightening setsthe desired dimensions of the base ring, in order to align the couplingelements of the base ring with those of valve 410, thereby enablingtight coupling, such as for the applications described with reference toFIG. 26.

For some applications, as shown in FIG. 26, base ring 422 comprises apartial ring, such as described hereinabove with reference to FIGS.2A-I, 19, 20, and 21. For other applications, as shown in FIGS. 25A-B,the base ring is arranged as a full ring, such as described hereinabovewith reference to FIGS. 4, 5, 7A-B, 10, 16A-B, 17, and 18B.

Valve prosthesis assembly 400 is typically implanted in a minimallyinvasive transcatheter or percutaneous procedure. The procedure beginswith the introduction and implantation of base ring 422 into the heart,such as using techniques for implanting implantable structure 22,described hereinabove with reference to FIGS. 2A-I. Prosthetic heartvalve 410 is subsequently introduced into the heart and coupled to basering 422, as described above. Valve prosthesis assembly 400 is typicallyused for replacement of a diseased native mitral valve, aortic valve,tricuspid valve, or pulmonary valve.

For some applications, system 20 further comprises a closure mechanism,such as described in above-mentioned US Patent Application Publication2012/0330411, with reference to FIGS. 16-17B thereof.

For some applications, system 20 further comprises a flexible pusherelement, such as described and shown in US Patent ApplicationPublication 2010/0286767, which is incorporated herein by reference,with reference to FIG. 8 thereof. The pusher element aids withaccurately positioning successive anchors 38 during an implantationprocedure, such as described hereinabove with reference to FIGS. 2H and21. For some applications, system 20 further comprises a pusher tubethat is applied to proximal end 49 of sleeve 26, such as described inthe above-mentioned '604 publication, with reference to FIGS. 14 and/or18A-B thereof. For some applications, system 20 further comprises asteerable tube, such as described in the above-mentioned '604publication, with referenced to FIG. 15 thereof, or with reference toFIG. 16 thereof. For some applications, system 20 further comprises apulling wire, such as described in the above-mentioned '604 publication,with referenced to FIG. 17 thereof. For some applications, system 20further comprises an external control handle, such as described in theabove-mentioned '604 publication, with referenced to FIG. 19 thereof.For some applications, contracting assembly 40 and implantable structure22 are configured as described with reference to FIG. 23 of theabove-mentioned '604 publication, mutatis mutandis.

For some applications of the present invention, system 20 is used totreat an atrioventricular valve other than the mitral valve, i.e., thetricuspid valve. For these applications, implantable structure 22 andother components of system 20 described hereinabove as being placed inthe left atrium are instead placed in the right atrium. Althoughimplantable structure 22 is described hereinabove as being placed in anatrium, for some application the implantable structure is instead placedin either the left or right ventricle.

The scope of the present invention includes applications described inthe following applications, which are incorporated herein by reference.In an application, techniques and apparatus described in one or more ofthe following applications are combined with techniques and apparatusdescribed herein:

-   -   PCT Publication WO 06/097931 to Gross et al., entitled, “Mitral        Valve treatment techniques,” filed Mar. 15, 2006;    -   U.S. Provisional Patent Application 60/873,075 to Gross et al.,        entitled, “Mitral valve closure techniques,” filed Dec. 5, 2006;    -   U.S. Provisional Patent Application 60/902,146 to Gross et al.,        entitled, “Mitral valve closure techniques,” filed on Feb. 16,        2007;    -   U.S. Provisional Patent Application 61/001,013 to Gross et al.,        entitled, “Segmented ring placement,” filed Oct. 29, 2007;    -   PCT Patent Application PCT/IL07/001503 to Gross et al.,        entitled, “Segmented ring placement,” filed on Dec. 5, 2007,        which published as PCT Publication WO 08/068756;    -   U.S. patent application Ser. No. 11/950,930 to Gross et al.,        entitled, “Segmented ring placement,” filed on Dec. 5, 2007,        which published as US Patent Application Publication        2008/0262609;    -   U.S. Provisional Patent Application 61/132,295 to Gross et al.,        entitled, “Annuloplasty devices and methods of delivery        therefor,” filed on Jun. 16, 2008;    -   U.S. patent application Ser. No. 12/341,960 to Cabiri, entitled,        “Adjustable partial annuloplasty ring and mechanism therefor,”        filed on Dec. 22, 2008, which published as US Patent Application        Publication 2010/0161047;    -   U.S. Provisional Patent Application 61/207,908 to Miller et al.,        entitled, “Actively-engageable movement-restriction mechanism        for use with an annuloplasty structure,” filed on Feb. 17, 2009;    -   U.S. patent application Ser. No. 12/435,291 to Maisano et al.,        entitled, “Adjustable repair chords and spool mechanism        therefor,” filed on May 4, 2009, which published as US Patent        Application Publication 2010/0161041;    -   U.S. patent application Ser. No. 12/437,103 to Zipory et al.,        entitled, “Annuloplasty ring with intra-ring anchoring,” filed        on May 7, 2009, which published as US Patent Application        Publication 2010/0286767;    -   PCT Patent Application PCT/IL2009/000593 to Gross et al.,        entitled, “Annuloplasty devices and methods of delivery        therefor,” filed on Jun. 15, 2009, which published as PCT        Publication WO 10/004546;    -   U.S. patent application Ser. No. 12/548,991 to Maisano et al.,        entitled, “Implantation of repair chords in the heart,” filed on        Aug. 27, 2009, which published as US Patent Application        Publication 2010/0161042;    -   U.S. patent application Ser. No. 12/608,316 to Miller et al.,        entitled, “Tissue anchor for annuloplasty ring,” filed on Oct.        29, 2009, which published as US Patent Application Publication        2011/0106247;    -   U.S. Provisional Patent Application 61/265,936 to Miller et al.,        entitled, “Delivery tool for implantation of spool assembly        coupled to a helical anchor,” filed Dec. 2, 2009;    -   PCT Patent Application PCT/IL2009/001209 to Cabiri et al.,        entitled, “Adjustable annuloplasty devices and mechanisms        therefor,” filed on Dec. 22, 2009, which published as PCT        Publication WO 10/073246;    -   U.S. patent application Ser. No. 12/689,635 to Zipory et al.,        entitled, “Over-wire rotation tool,” filed on Jan. 19, 2010,        which published as US Patent Application Publication        2010/0280604;    -   U.S. patent Ser. No. 12/689,693 to Hammer et al., entitled,        “Deployment techniques for annuloplasty ring,” filed on Jan. 19,        2010, which published as US Patent Application Publication        2010/0280605;    -   U.S. patent application Ser. No. 12/706,868 to Miller et al.,        entitled, “Actively-engageable movement-restriction mechanism        for use with an annuloplasty structure,” filed on Feb. 17, 2010,        which published as US Patent Application Publication        2010/0211166;    -   PCT Patent Application PCT/IL2010/000357 to Maisano et al.,        entitled, “Implantation of repair chords in the heart,” filed        May 4, 2010, which published as PCT Publication WO 10/128502;    -   PCT Patent Application PCT/IL2010/000358 to Zipory et al.,        entitled, “Deployment techniques for annuloplasty ring and        over-wire rotation tool,” filed May 4, 2010, which published as        PCT Publication WO 10/128503; and/or    -   U.S. patent application Ser. No. 13/167,476 to Hammer et al.,        filed Jun. 23, 2011, entitled, “Closure element for use with an        annuloplasty structure,” which published as US Patent        Application Publication 2012/0330410.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed hereinabove. Rather, the scope of the present inventionincludes both combinations and subcombinations of the various featuresdescribed hereinabove, as well as variations and modifications thereofthat are not in the prior art, which would occur to persons skilled inthe art upon reading the foregoing description.

1. A method comprising: providing an annuloplasty ring, which comprisesa flexible sleeve; during a percutaneous transcatheter procedure,placing the flexible sleeve entirely around an annulus of a mitral valveof a subject in a closed loop; fastening the sleeve to the annulus bycoupling a plurality of tissue anchors to a posterior portion of theannulus, without coupling any tissue anchors to an anterior portion ofthe annulus between left and right fibrous trigones of the annulus; andthereafter, contracting a longitudinal portion of the sleeve.
 2. Themethod according to claim 3, wherein the contracting assembly furthercomprises a longitudinal contracting member and a locking mechanism, andwherein the method further comprises, after contracting the longitudinalportion of the sleeve, locking the longitudinal contracting member withrespect to the contracting assembly using the locking mechanism.
 3. Themethod according to claim 1, wherein the annuloplasty ring furthercomprises a contracting assembly, and wherein contracting thelongitudinal portion of the sleeve comprises actuating the contractingassembly to contract the longitudinal portion of the sleeve.
 4. Themethod according to claim 1, wherein providing the annuloplasty ringcomprises providing the annuloplasty ring in which the sleeve is shapedso as to define an integrally closed loop having no sleeve ends.
 5. Themethod according to claim 1, wherein the sleeve has first and secondsleeve ends, and wherein placing the sleeve comprises: introducing theflexible sleeve into a left atrium while the first and the second sleeveends are not coupled to each other; and thereafter, in the left atrium,arranging the flexible sleeve entirely around the annulus to form theclosed loop.
 6. The method according to claim 5, wherein theannuloplasty ring further comprises an elongated linking member, whichis coupled to and disposed within the sleeve, and wherein placing theflexible sleeve entirely around the annulus comprises placing thelinking member along the anterior portion of the annulus.
 7. The methodaccording to claim 6, wherein the linking member is configured as aspring. 8-10. (canceled)
 11. The method according to claim 6, whereinthe linking member is substantially longitudinally non-extensible. 12.The method according to claim 6, wherein the linking member comprises afirst coupling element, wherein the annuloplasty ring comprises a secondcoupling element, which is configured to be coupleable to the firstcoupling element, and which is coupled to the annuloplasty ring within1.5 cm of one of the first and the second sleeve ends, measured when thesleeve is fully longitudinally extended, wherein the first and thesecond coupling elements are configured to provide an adjustable-lengthconnection between the linking member and the one of the first and thesecond sleeve ends, and wherein placing the linking member along theanterior portion of the annulus comprises setting an effective length ofthe linking member while coupling the first and the second couplingelements together.
 13. The method according to claim 6, wherein thelinking member is disposed within a longitudinal portion of the sleeve,wherein the annuloplasty ring further comprises an elongatedradial-force application element, which is disposed within thelongitudinal portion of the sleeve, and wherein placing the linkingmember comprises placing the elongated radial-force application elementalong the anterior portion of the annulus, such that the elongatedradial-force application element applies a force against a wall of thelongitudinal portion of the sleeve in at least one radially-outwarddirection.
 14. The method according to claim 13, wherein placing theelongated radial-force application element comprises placing theelongated radial-force application element along the anterior portion ofthe annulus, such that the elongated radial-force application elementpushes the longitudinal portion of the sleeve against atrial tissue. 15.The method according to claim 13, wherein the elongated radial-forceapplication element is springy.
 16. (canceled)
 17. The method accordingto claim 13, wherein the linking member is not configured as a spring.18. The method according to claim 13, wherein placing the linking membercomprises placing the linking member such that the linking member doesnot apply any force to the wall of the longitudinal portion of thesleeve.
 19. The method according to claim 13, wherein at least 90% of alength of the linking member is straight when in a resting state. 20.The method according to claim 13, wherein the linking member issubstantially longitudinally non-extensible.
 21. (canceled)
 22. Themethod according to claim 13, wherein the longitudinal portion of thesleeve is a first longitudinal portion of the sleeve, wherein theannuloplasty ring further comprises a contracting assembly, whichcomprises (a) a contracting mechanism, and (b) a longitudinalcontracting member, which is arranged along a second longitudinalportion of the sleeve that is entirely longitudinally distinct from thefirst longitudinal portion of the sleeve, and wherein the elongatedradial-force application element is disposed entirely within the firstlongitudinal portion of the sleeve.
 23. A method comprising: providingan annuloplasty ring, which comprises a flexible sleeve; during apercutaneous transcatheter procedure, placing the flexible sleeveentirely around an annulus of a mitral valve of a subject in a closedloop; fastening the sleeve to the annulus by coupling a plurality oftissue anchors to the annulus, with: a first non-zero longitudinaldensity of the tissue anchors along a posterior portion of the annulusbetween left and right fibrous trigones of the annulus, including thetrigones, which density is equal to (a) a number of the tissue anchorscoupled to the annulus along the posterior portion of the annulusdivided by (b) a length of the posterior portion of the annulus, and asecond non-zero longitudinal density of the tissue anchors along ananterior portion of the annulus between left and right fibrous trigonesof the annulus, not including the trigones, which density is equal to(a) a number of the tissue anchors coupled to the annulus along theanterior portion of the annulus divided by (b) a length of the anteriorportion of the annulus, wherein the first longitudinal density isgreater than the second longitudinal density; and thereafter,contracting a longitudinal portion of the sleeve.
 24. The methodaccording to claim 25, wherein the contracting assembly furthercomprises a longitudinal contracting member and a locking mechanism, andwherein the method further comprises, after contracting the longitudinalportion of the sleeve, locking the longitudinal contracting member withrespect to the contracting assembly using the locking mechanism.
 25. Themethod according to claim 23, wherein the annuloplasty ring furthercomprises a contracting assembly, and wherein contracting thelongitudinal portion of the sleeve comprises actuating the contractingassembly to contract the longitudinal portion of the sleeve.
 26. Themethod according to claim 23, wherein the first longitudinal density isat least twice the second longitudinal density.
 27. The method accordingto claim 23, wherein providing the annuloplasty ring comprises providingthe annuloplasty ring in which the sleeve is shaped so as to define anintegrally closed loop having no sleeve ends.
 28. The method accordingto claim 23, wherein the sleeve has first and second sleeve ends, andwherein placing the flexible sleeve comprises: introducing the flexiblesleeve into a left atrium while the first and the second sleeve ends arenot coupled to each other; and thereafter, in the left atrium, arrangingthe flexible sleeve entirely around the annulus to form the closed loop.29. The method according to claim 28, wherein the annuloplasty ringfurther comprises an elongated linking member, which is coupled to anddisposed within the sleeve, and wherein placing the flexible sleeveentirely around the annulus comprises placing the linking member alongthe anterior portion of the annulus. 30-32. (canceled)
 33. The methodaccording to claim 29, wherein the linking member comprises a firstcoupling element, wherein the annuloplasty ring comprises a secondcoupling element, which is configured to be coupleable to the firstcoupling element, and which is coupled to the annuloplasty ring within1.5 cm of one of the first and the second sleeve ends, measured when thesleeve is fully longitudinally extended, wherein the first and thesecond coupling elements are configured to provide an adjustable-lengthconnection between the linking member and the one of the first and thesecond sleeve ends, and wherein placing the linking member along theanterior portion of the annulus comprises setting an effective length ofthe linking member while coupling the first and the second couplingelements together.
 34. The method according to claim 29, wherein thelinking member is disposed within a longitudinal portion of the sleeve,wherein the annuloplasty ring further comprises an elongatedradial-force application element, which is disposed within thelongitudinal portion of the sleeve, and wherein placing the linkingmember comprises placing the elongated radial-force application elementalong the anterior portion of the annulus, such that the elongatedradial-force application element applies a force against a wall of thelongitudinal portion of the sleeve in at least one radially-outwarddirection.
 35. The method according to claim 34, wherein placing theelongated radial-force application element comprises placing theelongated radial-force application element along the anterior portion ofthe annulus, such that the elongated radial-force application elementpushes the longitudinal portion of the sleeve against atrial tissue. 36.The method according to claim 34, wherein the elongated radial-forceapplication element is springy.
 37. (canceled)
 38. The method accordingto claim 34, wherein the linking member is not configured as a spring.39. The method according to claim 34, wherein placing the linking membercomprises placing the linking member such that the linking member doesnot apply any force to the wall of the longitudinal portion of thesleeve.
 40. The method according to claim 34, wherein at least 90% of alength of the linking member is straight when in a resting state. 41.The method according to claim 34, wherein the linking member issubstantially longitudinally non-extensible.
 42. (canceled)
 43. Themethod according to claim 34, wherein the longitudinal portion of thesleeve is a first longitudinal portion of the sleeve, wherein theannuloplasty ring further comprises a contracting assembly, whichcomprises (a) a contracting mechanism, and (b) a longitudinalcontracting member, which is arranged along a second longitudinalportion of the sleeve that is entirely longitudinally distinct from thefirst longitudinal portion of the sleeve, and wherein the elongatedradial-force application element is disposed entirely within the firstlongitudinal portion of the sleeve. 44-224. (canceled)